Applying and Using Unique Unclonable Physical Identifiers

ABSTRACT

In a general aspect, unique unclonable physical identifiers are applied and used. A method of applying the unique marker can include receiving an object having a surface feature and forming a unique marker on the surface feature of the object. The unique marker includes a distribution of elements and conforms with a morphology of the surface feature. The method further includes extracting orientation information from the unique marker. The orientation information can indicate relative spatial orientations of the respective elements. The method additionally includes generating a unique code for the object based on the orientation information. The surface feature can be facets, surface patterns, textures, or other indentations of the object. The surface feature can include a region of the object that is susceptible to tampering.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationSer. No. 62/930,875, filed on Nov. 5, 2019 and entitled “ShapingIdentifier Tags to Surface Morphology,” and U.S. Provisional PatentApplication Ser. No. 62/934,283, filed Nov. 12, 2019 and entitled“Adhesive Identifier Tags,” and U.S. Provisional Patent Application Ser.No. 62/934,298, filed Nov. 12, 2019 and entitled “Tamper-EvidentIdentifier Tags,” the disclosures of which are hereby incorporated byreference in their entirety.

BACKGROUND

The following description relates to applying and using uniqueunclonable physical identifiers.

Some products are produced with holograms, watermarks, fluorescent dyesor other features that can be used as anti-counterfeiting measures. Forexample, such features may be used to verify the source or authenticityof products. Such measures are important in a number of industriesincluding food, pharmaceuticals, electronics, luxury goods and others.

DESCRIPTION OF DRAWINGS

FIG. 1A illustrates an example article with a unique marker.

FIG. 1B schematically illustrates the example unique marker of FIG. 1A.

FIG. 2A schematically illustrates an example particle comprised of adiamond crystal containing a defect center.

FIG. 2B schematically illustrates an NV-defect center in the examplediamond crystal lattice of FIG. 2A.

FIG. 3 schematically illustrates an example random distribution ofparticles in or on a host material in a unique marker.

FIG. 4 schematically illustrates an example scanner system for measuringthe position and orientation of particles in a unique marker.

FIG. 5 illustrates particle positions in an example image obtained froma fluorescence scan.

FIG. 6 schematically illustrates example particle orientations in a hostmaterial in a unique marker.

FIG. 7 illustrates example particle reference frame orientations usedfor calculating particle orientations.

FIG. 8 illustrates an example magnetic resonance response of particlessuch as NV-center in diamond.

FIGS. 9A and 9B schematically illustrate example magnetic scanconfigurations.

FIG. 10 schematically illustrates an example parametrization of particlepositions and orientations.

FIGS. 11A and 11B illustrate comparison of two example particle positionand orientation sets.

FIG. 12 is a flow diagram schematically illustrating an example processfor making an original scan of a unique marker.

FIG. 13 is a flow diagram schematically illustrating an example processfor making a destination scan of a unique marker.

FIG. 14 is a flow diagram schematically illustrating an example processfor using orientation information extracted from an object.

FIG. 15 is a flow diagram schematically illustrating an example processfor generating a unique code for an object.

FIG. 16 is a flow diagram schematically illustrating an example processfor analyzing an object.

FIG. 17 is a flow diagram schematically illustrating an examplechallenge-response process.

FIGS. 18A and 18B are diagrams of an example object having an exampleunique marker that is shaped to the surface morphology of the object.

FIG. 19A is a schematic diagram of an example object having an indentedlogo.

FIGS. 19B, 19C, 19D, and 19E are illustrations of an example process offorming a unique marker in the indented logo shown in FIG. 19A.

FIG. 20A is a schematic diagram of an example flexography printingsystem.

FIG. 20B shows a zoomed-in top-down view of some cells that are designedto have different dimensions so that unique markers with a specifiedshape can be created.

FIG. 21 is a schematic diagram of an example rotogravure system.

FIG. 22A is a diagram of a single tag prior to its application on anunderlying object or interface.

FIG. 22B is a diagram showing multiple single tags arranged in the formof a tape or roll.

FIG. 23 shows an example where a distribution of elements is placedwithin an adhesive that is not fully cured.

FIG. 24 shows an example where both a distribution of elements and asealant material are incorporated into a handheld applicator having anozzle or tip.

FIGS. 25A and 25B show examples where a distribution of elements may beincorporated into a sealant to seal interfaces and electronicenclosures.

FIGS. 26A and 26B show examples where elements are distributed in only aportion of a sealant.

FIGS. 27A and 27B show example processes for forming a conformal coatingon an underlying substrate or object.

FIG. 28 shows an example where an enclosure is provided with a gaskethaving a distribution of elements.

FIG. 29 shows an example of a tagged area that can be used toauthenticate identity and to provide evidence of tampering.

FIG. 30 is a diagram of a box that includes a unique marker on an edgeof the box.

FIG. 31 is a diagram of a box that includes a unique marker on a seam ofthe box.

FIG. 32 is a diagram of a film that includes a unique marker, where thefilm is placed over an object to produce a shrink-wrapped product.

FIG. 33 is a diagram of a fastener having a unique marker placed on aclutch of the fastener.

FIG. 34 is a diagram of an article's enclosure having a unique markerplaced on a seam of the enclosure.

FIG. 35 is a diagram of a microchip provided with unique markers atsolder points.

FIG. 36 shows an example where a unique marker can be used to provideevidence of use or activation of an object.

FIG. 37 shows an example where a unique marker can be used to provideevidence of an external force applied to a tagged surface.

FIG. 38 is a flow diagram schematically illustrating an example processfor forming and using a unique marker that conforms with a surfacemorphology of an object.

FIG. 39 is a flow diagram schematically illustrating an example processfor forming and using a sticker including a distribution of elements ona substrate having an adhesive backing.

DETAILED DESCRIPTION

In some aspects of what is described here, unique unclonable physicalidentifiers are applied and used. In some implementations, a uniquemarker is shaped to a morphology of an object's surface feature. Thesurface feature can be facets, surface patterns, textures, or otherindentations of the object. In some instances, the object has multiplesides or faces, and a facet can be one of the multiple sides or faces ofthe object. For example, the object can be a gem, and a facet can be oneof the multiple sides or faces of the gem. The unique marker can beapplied to or incorporated into the object (which may also be referredto as an article). In some implementations, the unique marker mayinclude elements distributed in or on a host material that is applied toor incorporated into the object. The elements may include crystallineparticles (e.g., micron-scale or nano-scale diamond particles) or othertypes of elements. The unique marker can be physically unclonable, thusallowing the unique marker to be a taggant for the object. For example,the orientations of the elements may be randomly distributed, and theelement sizes and relative positions can be regular or randomlydistributed. In some examples, making a copy of the object having amarker with a similar composition and orientation of elements issufficiently unlikely such that the object having the unique marker canbe considered distinct or unique. In some instances, the unique markeris a sticker including a distribution of elements on a substrate havingan adhesive backing, and at least a portion of the sticker is applied toan object.

The unique marker can be used to analyze the object. In some examples,analyzing the object using the unique marker includes authenticating theidentity of the object, determining whether the object has been tamperedwith, determining whether the object has been used or activated,determining whether the object has been exposed to environmental stress,determining whether the object has been subjected to mechanical stressor wear, or other types of analysis of the object. Various types ofobjects can be analyzed using the methods and systems discussed herein.Non-limiting illustrative examples of objects include bank notes andcertificates, credit cards and alike, electronic payment systems, votingsystems, communication systems and elements, jewelry and collectables,diamonds and gems, packaging, paper products, electronic equipmentcases, electronic components and systems (e.g., integrated circuits,chips, circuit boards), retail goods (e.g., handbags, clothing, sportsequipment), industrial components and systems (e.g., machine parts,automotive parts, aerospace parts), raw materials (processed orunprocessed) (e.g., ingots, billets, logs, slabs), food products andpackaging (e.g. wines, spirits, truffles, spices), pharmaceuticals,pharmaceutical packaging and lots, medical devices and surgical toolsand their packaging, official documents (e.g., contracts, passports,visas), digital storage systems and elements, mail and postal packaging,seals and tamper-proof labels. This list of example objects is notexhaustive, and many other types of objects can be analyzed using themethods and systems disclosed herein.

In some aspects of what is described here, a unique code can begenerated based on the elements of the unique marker. In some instances,one or more properties of the elements can be determined (e.g., byscanning the elements) to generate the unique code, which can then beused, for example, to analyze the object. For instance, the spatialorientations, locations, or sizes of the elements may be extracted fromthe unique marker to generate the unique code, although other types ofproperties of the elements may be used to generate the unique code. Theunique code can be used to analyze the object in a similar way asbarcodes and quick-response (QR) codes are currently used to readilyidentify objects. Therefore, the unique marker may be used as a“fingerprint,” for instance, when attached to or incorporated into theobject, enabling the object to be analyzed.

The unique marker may be formed using one or more methods describedhere. In some aspects of what is described here, the unique marker canbe shaped to the surface morphology of the object. For example, theunique marker may be shaped to surface patterns, textures, or otherindentations of the object. In some instances, shaping the unique markerto the surface morphology of the object includes providing a fluid(e.g., a liquid or viscous fluid) that contains a distribution ofelements (e.g., crystalline particles or other types of elements), andcuring the fluid to form the unique marker. In some implementations, thefluid (containing the distribution of elements) cures in the surfacepatterns, textures, or other indentations of the object to become theunique marker. In some implementations, the fluid is transferred from apattern of cells onto a substrate to create the unique marker.

In some aspects of what is described here, a distribution of elements(e.g., crystalline particles or other types of elements) may beincorporated into an uncured or semi-cured material. In someimplementations, the material can be an adhesive or a sealant material,and the uncured or semi-cured material can have a gel-like consistency.The uncured or semi-cured material can be applied to the object toconformally coat one or more components of the object, or to cover orfill a seam of the object. The uncured or semi-cured material issubsequently exposed to a process (e.g., ordinary drying, curing, byexposure to an energy source (e.g. UV radiation), or another process)that causes the material to solidify, thus allowing the adhesive orsealant material (containing the distribution of elements) to gain aphysically unclonable identity while maintaining its functional purpose(e.g., decorative, informative, protective, etc.) within the design ofthe underlying object. Additionally, utilizing an adhesive or sealantoffers an efficient and bespoke way to incorporate the distribution ofelements onto a surface that was not previously designed to host theunique marker, for example, in a custom tagging campaign.

In some aspects of what is described here, a unique marker that includesa distribution of elements can be used to demonstrate evidence oftampering with or use of a tagged object.

The systems and techniques described here can provide technicaladvantages and improvements. For example, unique markers that are shapedto a surface's morphology can provide a covert, simple,aesthetically-pleasing, and secure manner for analyzing the object(e.g., product tracking, authentication, etc.). By integrating a uniquemarker onto the surfaces of a packaging or a product itself, businessesmay be able to track their raw materials, components and products (e.g.,throughout the entire product lifecycle) in a secure manner. In somecases, products can be tracked using a mechanism that is not easilycompromised, and does not interfere with the product's function oraesthetic. In some cases, a unique code can be read repeatedly andquickly from unique markers that are shaped to a surface's morphology,which may allow more efficient and reliable serialized trackinganalysis. Unique markers that are shaped to a surface's morphology canalso be integrated into a product in a manner that is compatible withexisting manufacturing techniques and product features. In some cases,unique markers that are shaped to a surface's morphology can be used tointegrate a product's unique identifier (e.g., serial number, etc.) intoimpressed branding, logos, graphics, trademarks, or other visualfeatures of the product. In some cases, the unique marker can beintegrated into crevasses or hidden features within a product's surface,for example, to obscure its presence or shield it from environmentalexposure. Further, in some implementations, unique markers that areshaped to a surface's morphology can be mass-produced with consistentshapes for labelling.

In some implementations, articles are analyzed as follows. Afterapplying a unique marker to the article, an initial or ‘origin’ scan isperformed with an origin scanner that registers the relative positionand orientation of the crystals in an origin position-and-orientationmap. In some implementations, this is done by conducting a magneticresonance measurement of fluorescent atomic defects in the crystals, inparallel for each crystal, under known applied magnetic fields. In somecases, in addition to the position and orientation of the crystals, thesize of each crystal is determined and registered for use in analysis ofthe article. Particle orientation can be calculated from the projectionof the magnetic field vector along the defect center axis. Theorientation information does not have to be complete; partialprojections of orientations may be used. Orientation information can bethought of geometrically. The defect-center can be represented as a unitvector originating at its center. The orientation of the vector can bedescribed using spherical coordinates around its origin. The longitudeand latitude coordinates can be fully or partially described and known.In some examples, the orientation information is interrogated bymeasuring the Zeeman shift of the defect center to a magnetic field thatits magnitude and orientation is known. Partial orientation informationcan be deduced by a single measurement where the defect centerorientation is projected onto the magnetic field plane. Full orientationinformation can be extracted by combining several such measurements atdifferent magnetic field orientations.

Once article analysis (e.g., authenticating the identity of the article,determining whether the article has been tampered with, determiningwhether the article has been used or activated, determining whether thearticle has been exposed to environmental stress, determining whetherthe article has been subjected to mechanical stress or wear, etc.) isdesired (e.g. once the article reaches a destination), the unique markeron the article is scanned in a similar fashion to the initial scan (butnot necessarily with the same magnetic field or fields configuration),and the second scan is used to determine the relative position andorientation of the crystals. Partial or complete orientation informationis calculated based on predetermined settings of the magnetic field atthe time of the second scanning. This calculation results in theorientation map of the marker that can be compared with the known mapfrom a prior scan (e.g., the original scan).

One example comparison would be to find the set of position values onthe prior scan (origin) map where each corresponding position on thecurrent scan (destination) map of the set differs by no more than avalue, V. For example, V can be a fraction of each particle's size. Forthe particles in this subset, their orientations can be found in theorientation map. The angle between the particle orientation in theorigin map and the particle orientation in the destination map can becalculated. Only particles in the subset whose angle difference is lessthan a predetermined threshold value, W, chosen with constraint fromconditions of the destination scanner (e.g. magnetic field strength,detection time, etc.) qualify as a match. If the two maps exceedthreshold criteria for matching, the article at the destination can beconsidered to be: authentic and uniquely identified; not tampered with;not used or activated; not exposed to environmental stress; notsubjected to mechanical stress of wear; or the like. One thresholdcriterion might be the fraction of matching particles being 90% of thetotal number of particles in the origin position map.

In some implementations, the crystalline particles in a unique markercontain fluorescent color-centers such that their positions and sizescan be obtained using standard imaging techniques. The orientation ofthe crystalline particles can also be determined using a variation ofstandard fluorescence microscopy combined with magnetic resonancetechniques. The relative orientations of the particles may be random(the relative positions and sizes of the particles may also be random),and a large enough collection of particles will generally be unique anddistinct in its attributes.

The properties of the nitrogen-vacancy center (NVC) in diamond and othercrystalline particles containing color-centers may be exploited for usein unique markers and other objects in some instances.

Several unique combinations of crystalline particle hosts andcolor-centers enable a magnetic resonance response yielding orientationinformation about the particle as well as its position and size. The NVCin diamond is one example of a color-center that exhibits opticallydetected magnetic resonance. The NVC exhibits a broad fluorescenceresponse in the 635 nm-800 nm optical wavelength range when excited withoptical radiation below 600 nm (typically near 530 nm). Due to thesymmetry of the diamond lattice and the composition of the NV, theelectronic ground state of this center is a spin triplet with anintrinsic crystal field that splits the energy of the 0 spin sublevelfrom the two spin 1 sublevels. This energy splitting is in the microwaveregime, near 2.8 GHz, where transitions between the 0 and ±1 sublevelsare driven by resonant excitation. With a magnetic field applied alongthe NV-symmetry axis, the ±1 sublevels shift in energy in proportionwith the magnitude of the applied magnetic field (Zeeman Effect). Thisresults in two different frequencies satisfying a resonance condition.Inversely, if the field orientation is known, the orientation of thecrystal containing the NV can be obtained through measurement of theresonance frequencies and back-calculating the projection onto the NVaxis. In addition, the triplet/single electronic structure of the NVCfacilitates the measurement of the magnetic response. After brief (<5μs) illumination of optical radiation (<600 nm wavelength) the relativepopulations of the 0,±1 spin sublevels change and polarizepreferentially to the 0 state after a few microseconds at the cessationof illumination due to intrinsic interconversions between singlet andtriplet states. Moreover, such interconversions result in discriminationof the spin-sublevel populations, as the ±1 sublevels result in ˜30%less fluorescence than the 0 spin sublevel.

FIG. 1A illustrates an example article, in this example a sneaker 101,having a unique marker 103 a incorporated into the article, which may beused to analyze (e.g., validate the authenticity of) the article. Theunique marker 103 a can be incorporated onto the article in a variety ofways including, e.g., in a logo 102 as shown in the FIG. 1A. It may alsobe incorporated into a label or elsewhere in the article and need not bevisible to the naked eye. The unique marker (UM) under amplemagnification 103 b and with the technique mentioned below can be usedto reveal the orientation 105 and relative positioning 106 of acollection of particles 104 in the UM.

In some cases, the uniqueness of a marker is derived from the relativepositioning and orientation of particles or other elements within thehost material. FIG. 2A schematically illustrates a crystalline particle202, which contains at least one defect-center (also known as acolor-center) 201 that emits fluorescent light. One example of acrystalline particle host is diamond, composed of a regular repeatedstructure of carbon atoms 203 as shown in FIG. 2B. One example of acolor-center in diamond is the nitrogen vacancy center 204, whichconsists of a carbon of the lattice replaced with a nitrogen and anearest neighbor carbon to that nitrogen being removed entirely. Theorientation of the color center may be defined, for example, by thevector from the nitrogen atom to the vacancy. In some instances, thesymmetry of the lattice and four-fold symmetry of an NV center maypreclude absolute knowledge of the crystal orientation, and the relativeorientation of two centers may be known with two-fold symmetry.

FIG. 3 shows an extended film or volume of host material 301 containingmany particles of which a subset bears at least one color-center 302.The separation of those particles as well as the orientation of theparticles can be arbitrary.

Information on the separation and orientation of the particles can beobtained by imaging the unique marker using conventional opticalmicroscopy techniques. FIG. 4 schematically illustrates an examplescanner used for determining the separation and orientation of theparticles. In the example shown, a unique marker (a composite of hostfilm and particles) 401 is illuminated with a light source 402, such asa laser, which is reflected and transformed through a set of standardoptical components 406 and through a focusing objective 407. Thefocusing objective 407 is configured to provide magnification of theparticles' fluorescence sufficient to resolve the field of view ofinterest of the unique marker. This may be the entire unique marker or aregion of interest of the unique marker. After proper filtering of theillumination source from the fluorescence and image formation withstandard filters and optics 406, an image of the host plane is capturedon an imaging unit 405, such as, e.g., a CMOS or CCD camera. FIG. 5shows an example image 500, from which the positions from a fixedcoordinate system 501 and relative distances 502 between particles canbe obtained. This is one example of several possible techniques forreading the unique marker.

The orientation of the particles can be determined by observingfluorescence changes of the particles due to the relative orientation ofelectromagnetic fields oriented in the scanner reference frame relativeto the particle. One example is changing the transverse opticalpolarization of the propagating electromagnetic radiation (i.e.,illumination light) to be linearly or circularly polarized usingstandard waveplates in the optics system 406. This has an effect in manycrystalline materials containing color-centers including the diamond-NVsystem in 203. Alternatively, the response of the NVC (properly, thenegatively charged NVC) to a magnetic field can also provide informationabout the orientation. This is observed through an intrinsic magneticresonance condition in the microwave RF regime. The magnet module of thescanner 409, tunes the magnitude and orientation of the magnetic fieldapplied to the unique marker. The microwave antenna 404 and RF signalgenerator 403 output frequency are tuned to the changing resonancecondition of the magnet. A main logic module 408 controls the output ofthe laser (e.g., amplitude, time-dependent modulation), the microwave orRF fields (e.g., amplitude, phase, resonance frequency), and themagnetic field orientation and magnitude in a coordinated fashion suchthat a set of fluorescence images can be used to determine the particleorientation.

The resulting image can be similar to an optical image taken with atelescope (in the visible light spectrum) of the sky at night on oneparticular night: a mostly dark background with a variety of brightspots sizes and many separations between spots. The position of any onestar, planet or celestial body in the sky can be described by itsdisplacement from a reference celestial body, say the North Star(Polaris), assuming the observation point on the surface of the Earth isknown. Similarly, registration markings (e.g., fiducial markings) in theunique marker can guide the positioning of the scanner to aid inobtaining reproducible images of the same unique marker taken atdifferent instances in time or at different locations using similar, butnot necessarily identical, optical scanner systems. The positions offluorescing particles in the scan can be determined with respect tothese registration markers to give an absolute measure of their locationin the marker. One example of a registration marker is printing (e.g.,using inkjet technology) a “+” symbol with an indelible ink that absorbsgreen light and fluoresces at wavelengths similar to the NVC.

The location of a single bright spot in the image of the UM can beexpressed by using a regularly spaced Cartesian grid system 501 assignedto the pixels of the image. A location can be specified as an orderedpair (X_(a), Y_(a)), where X is the pixel coordinate of particle a alongone dimension and Y is the coordinate along the orthogonal dimension503. X_(a) and Y_(a) can be integers or real numbers. The set of orderedpair locations {(X_(a), Y_(a)), (X_(b), Y_(b)), . . . , (X_(zz),Y_(zz))} with respect to a given absolute origin point (0,0) specifies aunique description of the particle locations of the image. If theabsolute origin point is not specified, creating a label for eachordered pair and defining the vector separating the two particles alsoobtains a unique description of the particle positions. For example, ifthe particle at point (X₂, Y₂) is labeled “2” and (X₃, Y₃) is labeled“3”, then a unique identifier would be “Δ₂₃”=(X₂-X₃, Y₂-Y₃). Bycalculating all pairwise vectors, there is a unique list of identifiers,L, for describing the locations of the particles that has the additionalproperty of being invariant to global translations of the gridcoordinate system. L is unique set for a given host film with arbitraryparticle separations.

In addition to the locations of the particles in the image, theindividual particles have an orientation with respect to the hostmaterial reference frame. In some cases, if it is assumed that the hostmaterial is an extended object, an origin point may be defined withinthe host material and a right-handed three-dimensional Cartesiancoordinate system reference frame can be defined at this origin 601 asshown in FIG. 6. Similarly, a separate right-handed Cartesian coordinatesystem may be defined for each crystalline particle within the hostmaterial. Accordingly, there is a unique coordinate transformation tomove between the particle coordinate system and the host materialcoordinate system. One example parameterization is the use ofdirectional cosines of the two systems, another parameterization is aset of Euler rotations. Similar to the naming convention describedabove, suppose that a particle at point (X_(A), Y_(A)) is labeled “A”and has a transformation matrix T_(a) that transforms vectors specifiedin the “A” frame 602 to the host reference frame. Likewise, a secondparticle at point (X_(B), Y_(B)) is labeled “B” and has a transformationmatrix T_(b) that moves from the “B” frame 603 to the host referenceframe. The transformation matrix serves to identify the orientation ofthe particle with respect to the coordinate frame. Similarly, the matrixT_(ab)=(T_(a)){circumflex over ( )}(−1)*T_(b) specifies the relativeorientation between the particle crystal frames “A” and “B” 701 as shownin FIG. 7. T_(ab) can also be obtained via the directional cosines ofthe angles between the orthogonal axes comprising the frames A and B.Due to the single crystal nature of the particles, color-centers withinthe particles have a fixed orientation with respect to the particlecoordinate systems. Thus, by measuring the orientation of thecolor-center with respect to the host material frame, it is possible todetermine the particles' orientation using similar coordinatetransformations between the color-center's coordinate axes and thecrystalline particle coordinate axes. By calculating all pairwisetransformations, there is a unique list M, of transformation matrices(e.g., “AB”, etc.) for describing the relative orientations of theparticles that has the additional property of being invariant to globalrotations of the host grid coordinate system. M is unique set for agiven host film with random particle orientation.

In instances where the crystal lattice of the particle possesses a highdegree of symmetry, there is freedom in specifying the color-centercoordinate system axes with respect to the crystal principle axes. Insuch cases it may not be possible to uniquely transform thecolor-center's orientation to the crystalline principle axes systemusing measurements of the color-center alone. In such cases it maysuffice to provide a parametrization of the coordinate transformationfrom the host material reference frame to only a single symmetry axis ofthe color-center. For example, this transformation can be parametrizedby three directional cosines between the symmetry axis and each of theCartesian coordinate axes. Another parameterization is a polar andazimuthal angle with the former defined as the angle between the zCartesian axis of the host reference frame and the symmetry axis and thelatter defined as the angle between the x Cartesian axis of the hostreference frame and the projection of the symmetry axis into the xyCartesian plane of the host reference frame.

Properties of certain color-centers embedded in crystalline particlescan be used to determine the orientation of those particles. As oneexample, consider the negatively charged nitrogen-vacancy color-centerin a diamond crystalline particle. The nitrogen atom and vacancy withinthe carbon lattice of diamond may define a directional vector with adistinct orientation with respect to the crystal lattice coordinateaxes. The photophysics of the color-center may exhibit a decrease influorescence when irradiated with an oscillatory radiofrequency fieldwhose frequency is tuned to an intrinsic resonance of the system 800 asshown in FIG. 8. For example, at a frequency of roughly f₀=2870 MHz, thephotoluminescence of the center decreases by ˜30%. Moreover, if amagnetic field is applied along the NV symmetry axis, this singleresonance splits into two resonances with distinct frequencies given byf₊=2870+2.8G and f⁻=2870-2.8G for a magnetic field projection ofstrength G gauss along the symmetry axis. To lowest order, fieldsorthogonal to this symmetry axis do not contribute to a shift infrequencies. Thus, by maintaining the magnitude of an external magneticfield and changing its direction in a known fashion with respect to acommon coordinate system, such as the host material coordinates, it ispossible to determine the absolute orientation of the crystallineparticle. With this information the distinct orientations of any twoparticles in the host material pairwise can be established using theaforementioned techniques.

Provided the number of particles within the host material is smallenough, fluorescent light emitted from each individual particle can bespatially localized using aforementioned microscopy techniques. Forinstance, when the host material contains a sparse distribution of theparticles (e.g., having a filling fraction of 20% or less), theresulting fluorescence image may contain more void than particle. Bysampling microwave frequencies near f₀ with the maximum and minimumfrequencies set by the known magnetic fields applied to the hostmaterial it is possible to measure the resonance response 800 for eachregion of interest of individual particles as shown in FIG. 8. Next, byapplying static magnetic fields 900 in different orientations withrespect to the host film reference frame, it is possible to determinethe orientation of individual particles from a series of magneticresonance responses. For example, the first orientation could be alongthe host material frame X axis 901 and the second orientation along thehost material frame Y axis 902 as shown in FIG. 9. A set of imagesacquired under these differing microwave frequencies and magnetic fieldorientations can provide a full scan and description of the spatiallocation and orientation of each particle in the host film 1000 as shownin FIG. 10. Each particle contains a unique location and orientationtransform matrix 1001. The full orientation of the unique marker can bedefined, for instance, as the set of coordinates and matrices for eachparticle for all i particles in the host film:{(X_(i),Y_(i),Z_(i),T_(i))}. Two random instances of particles set intheir respective host fields will have sets of full orientations that donot match thereby guaranteeing the uniqueness of a given set ofparticles.

In addition to position and orientation characteristics of the uniquemarker, additional uniqueness can optionally be derived from the sizeand shape of the particles. This can be done using image processingtechniques that analyze the shape (for example an outline) and relativesize (e.g., the length of the maximum axis) in the projected image ofthe particle.

As shown in FIG. 11, in some cases, a given unique marker can beidentified by a test measurement 1101 of the full orientation andmatching the set of particle positions and orientationss={(X_(i),Y_(i),Z_(i),T_(i)} to the known full orientation of the uniquemarker 1102 s0={(X_(i),Y_(i),Z_(i),T_(i)} with sufficient overlap toassure that the measured object is the same physical unique marker:|s−s₀|<ε 1103. Here |.| represents a collective distance measure for theset vectors, such as the norm, and £ represents a single parameterthreshold determining equivalence of two sets.

FIGS. 12 and 13 illustrate an example process for analyzing an article.

In a first example, two locations are involved in the identification.The origin 1200 is the place where the unique marker is first scanned.The complete position and orientation of the unique marker 1201 isobtained using the techniques described herein with a scanner 1204capable of applying arbitrary magnetic field configurations as used forthe complete scan. The unique marker is associated with a serial number1207 and is affixed to the article 1202 of interest. The completeposition information, orientation information 1206 and scanner settings1203 at the origin are associated with the serial number 1207 and storedsecurely. Such storage 1208 could be local to the origin or be locatedat a remote data center 1351 receiving the data over the Internet orother network. The unique article 1209 then leaves the origin.

At a destination 1300 (which may be a physical location separate fromthe origin or as discussed below at the same location as the origin), itis desired that the unique marker 1303 attached to the unique article1301 be identified and analyzed. In this example, the destinationqueries an authentication server 1350 over the Internet or other networkwith the serial number 1302 of the unique article in question. Theauthentication server retrieves the scan parameters from a securedatabase 1351 associated with the article serial number. The serverresponds to the destination with a set of challenge parameters for thescanner settings 1305, such as the test magnetic field configurationsand microwave frequency parameters, to which the scanner 1304 at thedestination should adjust. In this example, the field configurations aresufficient for the destination scanner to determine the set of positionsand orientations of each particle 1306 in the unique marker with respectto a coordinate system centered in the host film. The destinationscanner performs the series of scans similar to those completed at theorigin. It then provides a response to the authentication server 1350with the set of measured positions and orientations 1306 and serialnumber to the authentication server. The authentication server 1350 hasknowledge of the positions and orientations associated with the serialnumber and stored in the database 1351 and obtained from theinitialization scan at the origin scan. The server 1350 compares theorientation and position maps and performs the calculation of theoverlap of the two sets (the initialization scan and the destinationscan) and determines if the sets are close enough to be considered anauthentic match. In this example, the server 1350 responds with one oftwo outcomes 1307: Pass if the closeness criterion is met; and Fail forall other outcomes.

A single destination point of a unique article is given as anillustrative example for the first example. For particular applicationsand use cases (e.g., bank note authentication) a single destinationpoint may not exist as the unique article may continue to circulatebetween various parties and destination points. In addition, thedestination may not be at a physically separate location; uniquearticles can be initialized, stored and analyzed at a single physicalsite in a variation of the aforementioned analysis method.

In a second example, the origin scan of the article starts and commencesas described in the first example above 1200. At the destination, theunique article is received and the unique marker, as well as the serialnumber are retrieved from the article. In this second example, thescanner has a magnetic field that is not changeable but is of amagnitude and orientation known to the analysis system. The scanner unitis identified by a scanner serial number. With this single magneticfield configuration, the destination scanner performs a scan bycapturing successful fluorescence images of the unique marker, each witha different microwave frequency specified. The image positions andmagnetic resonance frequencies of each particle are recorded. Thisinformation is sent to the authentication server along with the articleserial number and the scanner identification number.

In this example, the authentication server knows the particle positionsand orientations of the unique marker associated with the serial numberas captured during the initialization scan. The authentication servercan calculate the expected magnetic resonance response for thisparticular unique marker by having knowledge of the applied magneticfield. Since the magnetic field associated with the scanner serialnumber provides this information by using a mathematical model for theNV center, the authentication server can determine the expected magneticresonance response for the combination of serial number and scannerserial. The expected magnetic resonance response is equivalent toobtaining partial and incomplete orientation of the particle. The scaninformation (particle positions and resonance frequencies) is sent tothe authentication server from the destination and compared with themodel calculated values. Using a similar thresholding criteria withsingle parameter £ as described above, the unique marker is deemed anauthentic match for the combination of article serial number and scannerserial number if the partial scan at the destination is sufficientlysimilar to the calculated partial scan at the authentication server.

In some instances, the analysis techniques described here may offersignificant advantages. For example, a hierarchical system foridentifying a physically unique distribution of fluorescing particles in1-, 2- or 3-dimensions may be used. Not only is the position of theparticles used, but the random orientation of the particles with respectto one another is used for the unique identification. Cloning a physicalfingerprint using both position and orientation information may beimpractical or even impossible, for example, using nanopositioningtools, such as an atomic force microscope, to perform aparticle-by-particle pick-and-place procedure to recreate a fingerprint.

In addition to the orientation, other physical properties of theparticles can optionally be observed from the fluorescence that add tothe security, uniqueness, and unclonability of a unique marker in somecases. These properties can include, but are not limited to, crystalstrain of each particle, spin dephasing times (e.g., T₂ times) of eachparticle, unique signatures of magnetic noise local to individualparticle environments, unique signatures of electric field noise localto individual particle environments, unique resonance signatures oflocal nuclear spin ensembles in particles (e.g., hyperfine splitting),and unique signatures of fluorescence lifetime due to local dipolefields resonant with the dipole energy of fluorescence (FRET).

In some cases, the techniques described here may avoid the need to relyon spectral signatures of fluorescence. Measuring spectral signatureswith small changes in wavelength involves large diffraction gratings andlong reflection paths limiting the practical usage of thesefingerprinting methods, especially in field deployable situations.

In some implementations, in conjunction with or separate frommeasurement of the magnetic resonance response of the color-centers inthe particles, the fluorescence intensity of the particles can be usedto gain information about particle orientation. For some magnetic fieldstrengths in the NV-color center, such as those above a few hundredGauss, it is observed that the fluorescence response “quenches” when alarge magnetic field component is applied orthogonal to the NV-centersymmetry axis. This technique enables gaining orientation informationwithout the use of RF or microwaves.

In some cases, an additional layer of security can be provided by theaddition of a magnetic particles or markers to, or near, the UM. Oneexample of a magnetic marker is a thin polymer film containingmagnetized superparamagnetic iron-oxide particles. In such cases, thedestination scanner approaches the unique marker under test to themagnetic marker, whereby the magnetic domains or particles on thesurface generate a local magnetic field across the field of view forscanning the unique marker. The unique marker is imaged in the mannerdescribed above and the magnetic resonance response is recorded.Magnetic markers may be considered unique by the same criteria foruniqueness set forth earlier in this document for unique markers. Aunique magnetic marker is characterized beforehand and information aboutthe magnetic field (magnitude and orientation) of the marker is storedat the authenticator 1350. With this information the authenticator cancalculate the anticipated response for a given scanner unique magneticmarker's identification number and the unique marker's serial number.The measured response at the destination scanner and the calculatedresponse are analyzed for their similarities and the authentication isdetermined by aforementioned threshold criteria.

In some implementations, the unique magnetic marker and the uniquemarker are fused into a combined physical marker. The magnetic particles(MP) can be embedded in the article, e.g., below the UM. The MP createsa particular magnetic field pattern near the UM. If the UM is removed orshifted from the original location the article, the desired analysis(e.g., authentication) will fail. In some implementations, the MP can beincorporated in the adhesive of the UM or in the suspension medium ofthe article.

In some implementations, the unique marker can serve as a physicallyunclonable function (PUF). PUFs operate by a challenge/response behaviorwhereby some parameters of the system can be varied (i.e., thechallenge) and the response of the physical system to those parameterscan be easily measured. Due to intrinsic randomness in the device, PUFsare difficult to clone. The randomness makes it difficult to predict theresponse of the physical system (i.e., function output) based on theinput (i.e., challenge) parameters as well. The unique marker can act asa PUF when placed in a parametrically controlled magnetic environment.As an example, the local magnetic field strength and orientation can bevaried by setting parameters, such as currents in a collection of tinycoils. The currents give rise to magnetic field inside the PUF. The PUFchallenge might be a set of current values for the coils and the PUFresponse would be the resonance frequency response for each particlewithin the unique marker.

In some implementations, the challenge parameters for setting themagnetic field need not be communicated between a destination scannerand the authenticator for each scan. Instead, the authenticator knows ofa unique random key seed installed at destination scanner. Theauthenticator and the destination scanner also share a commonsynchronized clock. The destination scanner then uses the clock valueand the random seed as inputs to a one-way (e.g., hash) function whoseoutput parameters set the magnetic field parameters. In such a scheme,the authenticator can determine the magnetic field parameters from themutual information known to both the scanner and authenticator andperform the threshold matching. Such randomization of the scannerparameters adds an additional layer of security.

In some implementations, the UM can be used as a unique fingerprint or aphysically unclonable function (PUF) for authentication and encryption.The orientation pattern generates a random bit string key that is usedto encode a message or as a seed to another encryption protocol.

In some implementations, instead of the authenticator providing a simplepass/fail message for authentication, the authenticator provides thedestination with the expected scanner response. The authenticatorresponds with a message containing the partial orientation informationfor the scanner/tag pair as calculated from the scanner serial numberand the complete orientation information of the UM captured at theinitialization scan at the origin during attachment to the article. Thedestination scanner does not send its measurements to the authenticator,but instead validates the scan it measures with the expected responseprovided by the authenticator. The destination compares the message withthe scan information and authenticates the object if the responsesatisfies the threshold criteria. The authentication step of comparingthe origin data and the destination data can be done at the destinationor in a system that receives the data from both scanners.

In some implementations, the unique marker can also be intentionallyaltered in its physical composition upon leaving the origin scan. As anexample, the scanner or another device may alter or modify the UM. Thosealterations can be done by physical deformation of the UM or by heatingit above a set temperature. For example, a laser beam can be used toheat an area in the UM and reflow the suspension medium such that theorientation and position of the particles changes. A full and completealteration can be used for marker reset such that previous scanners willnot match future scanners. In other words, the marker is reinitializedwithout the original scanner (or any prior system) having informationabout the UM new configuration.

In some implementations physical alteration can also be used to destroya UM after use (for single use applications). For example, the UM may beused to authenticate a seal on a package (e.g., as tamper-freeevidence). The seal is broken when the package is opened and the UM isno longer needed. To avoid attempts to reuse the marker, such as toattach an authentic UM to a non-unique article, the UM can be destroyed.

In some implementations, partial physical alteration may also be usedfor securing the chain of custody of the UM. As an example, a scanner(e.g., a destination scanner) may alter the UM partially to introduce avariation to some of the marker properties, such as the particlepositions and orientations in one region of the marker. Thesemodifications are measured at the modifying scanner and may be storedlocally or externally depending on the application needs. This can beused as a ledger to record scan events directly on the UM. The UMcontains enough information to authenticate the marker but includesadditional space/information/particles to allow for the recording andauthentication of the modified sections of the UM. This can be donemultiple times on the same UM. For example, this technique can be usedfor tracking of an article in a supply chain where different checkpointsscanners are used.

In some implementations, the UM is used as an encryption key whereby theunique marker is physically altered at the destination where theencrypted data is stored. The knowledge of the UM orientation may beknown at time of manufacture, but can be altered by the scanner at thepoint of encryption to deny other parties with prior custody of the UMfuture knowledge of the key. The unclonability of the key preventssurreptitious accessors from copying the key on site. In some examples,a device accepting cleartext (unencrypted) data requires a UM as a keyfor symmetric encryption/decryption.

In addition to the application of the unique markers described hereinfor authentication of objects, the unique markers can have otherapplications (which may be in combination with or an alternative toauthentication of objects). One example of application is multi-factorauthentication. The unique marker is unclonable and knowledge of itsproperties can be stored with an authentication server. A user seekingto authenticate a transaction, event, object, data, etc. can provideboth this physical marker (a key) and a password for proving his/heridentity. In another example, the user password is used to generate aparticular predetermined magnetic pattern in the scanner device and thusproviding an additional layer of security. The user ID, Scanner ID andmarker scan is shared with the authentication system. This is similar toa hardware security token with the exception of it not needed to bepowered, but requiring a dedicated reader device.

Another example application is generation of random bits used asencryption keys. The orientation and position information of a givenunique marker can be used to generate random bit strings used forencryption. Provided that the data associated with the unique marker isintentionally not stored, but only used at an origin location to derivethe random string, the physically unclonable key would be required todecrypt the information.

Another example application is determining whether the integrity of theobject has compromised. In some cases, the integrity of the object canbe compromised when the object has been tampered with, used, exposed toenvironmental stress, or exposed to mechanical stress or wear. Theunique marker can be applied to applied to or incorporated into anobject. As an example, the unique marker can conformally coat one ormore components of the object. As another example, the unique marker canbe shaped to surface patterns, textures, or other indentations of theobject. When the object's integrity has been compromised, the uniquemarker may be physically altered or deformed, thus changing one or moreproperties of the unique marker. A comparison of the unique marker'sproperties at various points along the object's chain of custody canreveal whether (and where along the object's chain of custody) theobject has been tampered with, used, or exposed to environmental stressor mechanical stress or wear. In some instances, a unique marker'sproperties may be obtained by generating a unique code, for example,according to the example processes 1400, 1500 shown in FIGS. 14 and 15,or another type of process. In some instances, a unique marker'sproperties may be obtained by generating orientation information, forexample, the orientation information 1206, 1306 shown in FIGS. 12 and13, or another type of orientation information. In some instances, aunique marker's properties may be obtained by visual or opticalinspection of the unique marker's integrity.

FIG. 14 is a flow diagram schematically illustrating an example process1400 using orientation information extracted from an object. The exampleprocess 1400 may include additional or different operations, includingoperations performed by additional or different entities, and theoperations may be performed in the order shown or in another order. Insome cases, one or more of the operations shown in FIG. 14 areimplemented as processes that include multiple operations, sub-processesor other types of routines performed by one or more systems. Forexample, the systems, components and processes shown in FIG. 1A, 1B, 2A,2B, 3-8, 9A, 9B, 10, 11A, 11B, 12, 13 or 15 can be used, in someinstances, to perform one or more of the example operations shown inFIG. 14. In some cases, operations can be combined, performed inparallel, iterated or otherwise repeated or performed in another manner.

FIG. 14 shows the example process 1400 performed by three entities: afirst entity 1402, a second entity 1404 and a third entity 1406. Theentities shown in FIG. 14 may represent distinct entities in amanufacturing process, an industrial process, a supply chain, adistribution channel, a financial process, a corporate workflow oranother type of process. As shown in FIG. 14, each entity obtains aunique code from the elements of the same object, and the unique code isthen used by the entity.

In some cases, the object in the example process 1400 can be or includea unique marker (UM), for instance, of the type described above. Forinstance, in some implementations, the object can be the sneaker 101 orthe unique marker 103 a shown in FIG. 1A, the unique marker 401 shown inFIG. 4, the article 1202 or the unique marker 1201 shown in FIG. 12, theunique article 1301 or the unique marker 1303 shown in FIG. 13. In somecases, the object can be or include another type of unique marker (UM)or another type of system, device or component that includes a UM. Insome cases, the object can be or include a tamper-evident device thatcan be used to verify the integrity of a structure.

In some examples, the first entity 1402 is a component manufacturer, thesecond entity 1404 is a system manufacturer, and the third entity 1406is a retail distributor. The object can be the component (or part of thecomponent) manufactured by the first entity 1402, and the second entity1404 can incorporate the component from the first entity 1402 into aproduct that is sold or distributed by the third entity 1406. The secondand third entities 1404, 1406 can use the unique code, for example, totrack and trace the component or to authenticate the source, the type oranother attribute of the component. As an example, the component couldbe a battery, a chipset, or another part for a consumer electronicsdevice, a medical device, etc.

In some examples, the first entity 1402 is a manufacturer or printer ofcommercial documents, and the second entity 1404 and the third entity1406 are financial institutions. The object can be the commercialdocument (or part of the commercial document) manufactured by the firstentity 1402. The unique code can be used, for example, to authenticatethe source, the type or another attribute of the commercial document.Examples of commercial document include cash, coins and other currencyor bank notes, checks, bonds, stock certificates, etc.

In some examples, the first entity 1402 is a manufacturer ofpharmaceuticals, medical devices or healthcare equipment, the secondentity 1404 is a distributor and the third entity 1406 is a healthcareprovider. The object can be the pharmaceutical, medical device orhealthcare equipment (or packaging for, or a component of thepharmaceutical, medical device or healthcare equipment) that ismanufactured by the first entity 1402 and distributed to health careinstitutions by the second entity 1404. The second and third entities1404, 1406 can use the unique code, for example, to authenticate thesource, the type, the intended recipient (e.g., a specific patient) oranother attribute of the medical device or healthcare equipment. As anexample, the medical device could be a prosthetic device or implantmanufactured or allocated for a particular patient.

In some examples, the first entity 1402 is a manufacturer of containers(e.g., vials, bottles, bins, shipping containers, etc.), the secondentity 1404 places some contents into the containers and entrusts thecontainers to the third entity 1406 for storage, analysis, transport,processing or another purpose. The object can be the container (or partof the container) that is manufactured by the first entity 1402 andprovided to the second entity 1404. The second and third entities 1404,1406 can use the unique code, for example, to authenticate the identityor contents of each individual container. As an example, the unique codecould be used to authenticate a biological sample of an individualpatient, a type of prescription drug or other sensitive contents. Asanother example, the unique code could be used to verify atamper-evident component of the container, for instance, to determinewhether the container or its contents have been tampered with.

In some examples, the unique code can be used to verify that the objectis authorized for handling or use by a specific entity or a group ofentities, for example, entities in a specific geographical region orentities with proper credentials.

At 1410, the first entity 1402 manufactures an object. In someimplementations, another entity (other than the first, second or thirdentities 1402, 1404, 1406 shown in FIG. 14) manufactures the object at1410 and then provides the object to the first entity 1402. The objectmay be manufactured by multiple entities in multiple locations, and themanufacturing performed at 1410 may represent one manufacturing processwithin an overall manufacturing workflow.

In the example shown in FIG. 14, when the object is manufactured, adistribution of elements is formed in the object. In some cases, themanufacturing process may control the density, sparseness or number ofelements in the object. In some examples, the elements are diamondparticles, and the object may be manufactured to have diamond particlesfilling less than a threshold percentage (e.g., less than 20%, less than10%, less than 1%, etc.) the object's volume. In some cases, the density(e.g., mass density, volume density) of elements in the object iscontrolled in a manner that allows the individual elements to beidentified by an imaging system, for instance, so that a fluorescenceimage of the object contains a sparse constellation of diamondparticles.

Here, the distribution of elements can be formed as a suspension ofelements on a two-dimensional surface of the object, or as a suspensionof elements within a three-dimensional volume of the object, or both. Insome cases, the suspension of elements is formed in the object bydistributing the elements on a surface (e.g., an external surface, aninternal surface, or both) of the object. In some cases, the suspensionof elements is formed in the object by distributing the elements in amedium of the object (e.g., in the material that the object is made of).The elements can be fixed in position, for instance, so that theelements remain static relative to each other and relative to the mediumof the object. For example, the suspension of elements can be a staticspatial distribution of elements, in which the relative locations,orientations, sizes, magnetic environments and other properties of theelements can remain fixed. In some implementations, the elements arefixed in position as long as the shape and structure of object remainsunchanged; and the positions of the elements can be modified, forexample, by deforming or otherwise changing the object, to modify therelative locations, orientations, sizes, magnetic environments and otherproperties of the elements.

In some examples, the elements are diamond particles, and a suspensionof diamond particles is formed in the object when the object ismanufactured at 1410. The suspension of diamond particles can be of thetype in the host material 301 shown in FIG. 3 or another type ofdistribution. The suspension of diamond particles may be formed, forinstance, by manufacturing systems that use source materials thatcontain diamond particles. For example, the manufacturing systems mayinclude injection molding systems, additive manufacturing systems,printers, paint application systems, saws, lathes, mills, and othermanufacturing systems. In some cases, the manufacturing systems may alsoinclude a mixer or another type of system that mixes or otherwisedistributes the diamond particles into a source material.

The suspension of diamond particles may be formed, for example, bydistributing the diamond particles on a surface of the object. Thediamond particles may be distributed on the surface of the object, forinstance, by mixing the diamond particles into a liquid, gas or otherfluid medium, and applying the liquid, gas or other fluid medium to thesurface of the object. In some cases, the diamond particles can be mixedwith aerosol paint in a pressurized container, and the aerosol paint canbe sprayed onto a surface (interior, exterior or both) of the object. Insome cases, the diamond particles can be mixed with latex-based paint,oil-based paint, or another type of paint that is brushed, rolled,sprayed or otherwise applied to a surface (interior, exterior or both)of the object. In some cases, the diamond particles may be distributedon the surface of the object by spin or dip coating processes used insemiconductor manufacturing.

The diamond particles may be distributed on the surface of the object,for instance, by mixing the diamond particles into conformal coatingmaterial, and applying the conformal coating material to the surface ofthe object. The conformal coating material may include an acrylic,silicone, urethane, or parylene material or another material of the typethat is typically applied to electronic components (e.g., printedcircuit boards, etc.). The conformal coating material can be sprayed,brushed or otherwise applied to a surface (interior, exterior or both)of the object.

The diamond particles may be distributed on the surface of the object,for instance, by mixing the diamond particles into toner or ink material(e.g., in a printer cartridge), and printing the toner or ink materialon the object. The toner or ink material may include material of thetype that is typically used in ink-jet printers, laser printers, etc.The toner or ink material can be printed on paper, fabric or othermaterial that forms all or part of the object, for example, by aconventional printer or another type of system.

The suspension of diamond particles may be formed, for example, bydistributing the diamond particles in a material and forming the objectfrom the material. The diamond particles may be distributed in thematerial, for instance, by mixing the diamond particles into a liquid,gas or other fluid medium, and forming the object from the liquid, gasor other fluid medium. For example, the diamond particles can be mixedwith source material (e.g., liquid or resin thermoplastic material,melted glass material, melted metal material, etc.), and the source canbe used in an injection molding process or additive manufacturingprocess to form the object. In a typical injection molding process, theheated source material is injected at high pressure into a cavitydefined by a mold, and the source material conforms to the mold and thencools and hardens in the shape of the cavity. In a typical additivemanufacturing process, the source material is deposited in successivelayers according to a computer model, and the layers are built up toform the object. The additive manufacturing process may be performed,for example, by a conventional 3D printer or another type of system.

The diamond particles can be mixed with source material (e.g., liquid orresin thermoplastic material, melted glass material, melted metalmaterial, etc.), and the source can be cooled or otherwise processed toform a solid workpiece from which the object is formed. For instance,the workpiece can be a plastic, metal or other type of solid workpiece,and the object can be formed by removing material (e.g., cutting,filing, sanding, milling, drilling, stamping, machining, etc.) theworkpiece. In some cases, conventional equipment (e.g., saws, files,lathes, mills, drills, etc.) can be used to machine the workpiece, forinstance, in a subtractive manufacturing process.

At 1412, the first entity 1402 obtains a unique code from the elementsof the object. For example, when the elements are diamond particles, thefirst entity 1402 may use the suspension of diamond particles togenerate a unique code for the object. The first entity 1402 can obtainthe unique code, for example, according to the example process 1500shown in FIG. 15 or another type of process. In some examples, theunique code can be based on (e.g., the unique code may be, include, bederived from, etc.) orientation information (e.g., the orientationinformation 1206 shown in FIG. 12, the orientation information 1306shown in FIG. 13) or another type of element information (e.g., magneticenvironment information, topographical information, locationinformation, etc.) extracted from the object. In some implementations,the unique code is obtained by a scanner system that extracts theelement information and a computer system that generates the unique codefrom the element information. For example, when the object includes asuspension of diamond particles, the element information may describethe orientations, locations, magnetic environments, or sizes of therespective diamond particles in the suspension, or the objectinformation may describe any combination of these properties of therespective diamond particles in the suspension.

At 1414, the second entity 1404 obtains the object. The second entity1404 may obtain the object directly from the first entity 1402 orindirectly through an intermediary entity. For example, the object maybe handled by a delivery service, customs or transport officials,another entity in a supply chain, etc. In some cases, the object maypass through one or more intermediate owners, trustees or other entitiesover a period of days, months or years between the first entity 1402 andthe second entity 1404.

At 1416, the second entity 1404 obtains a unique code from the elementsof the object. The second entity 1404 can obtain the unique code, forexample, according to the example process 1500 shown in FIG. 15 oranother type of process. In some implementations, the second entity 1404obtains the unique code using the same process that the first entity1402 used to obtain the unique code. For instance, the second entity mayhave access to the same type of scanner equipment, and the unique codemay be obtained by a protocol that is known to both the first entity1402 and the second entity 1404.

In some cases, a protocol for obtaining the unique code from the objectincludes parameters (e.g., magnetic field strength, illuminationintensity, scanner settings or other types of parameters), and theunique code produced by an execution of the protocol depends on theproperties of the object and the values of the parameters. In somecases, the first entity 1402 selects the values of the parameters thatit used (at 1412) to extract the unique code, and the second entity 1404uses the same values (at 1416) to extract the unique code. For example,the values may be provided with the object, obtained separately from thefirst entity 1402, received from a trusted third party, obtained from apublic database or otherwise procured by the second entity 1404. In somecases, the second entity 1404 independently selects the values of theparameters that it uses (at 1416) to extract the unique code, forexample, by selecting the values randomly, by using pre-defined values,or otherwise independent of the values used by the first entity toobtain the unique code (at 1412).

In some instances, the first and second entities 1402 and 1404 obtainthe same unique code at 1412 and 1416, respectively. For example, whenthe elements of the object have not been altered, and the extractionprotocol is executed properly, the unique code obtained by the secondentity 1404 (at 1416) may be identical to the unique code obtained bythe first entity 1402 (at 1412). In some instances, the first and secondentities 1402 and 1404 obtain different unique codes at 1412 and 1416,respectively. For example, when the elements of the object have beenaltered, or the extraction protocol is executed improperly, the uniquecode obtained by the second entity 1404 (at 1416) may be different fromthe unique code obtained by the first entity 1402 (at 1412).

At 1418, the second entity 1404 uses the unique code. In someimplementations, the unique code is used in a process for authenticatingthe object, tracking the object, verifying integrity of the object, oranother type of process related to the object. As an example, the uniquecode can be the orientation information 1306 in FIG. 13 that is used toauthenticate the unique article 1301. In some implementations, theunique code can be used in a process that is otherwise unrelated to theobject. In some instances, the unique code can be used as a qualitymeasure, as a security measure, and as an inventory management tool. Insome cases, the unique code can be used to demonstrate regulatorycompliance or for other purposes.

In some implementations, the second entity 1404 communicates with thefirst entity 1402 (or another entity) to use the unique code at 1418. Insome cases, the first and second entities 1402, 1404 communicate witheach other directly, for example, over a communication channel or adirect communication link. Example communication channels include wiredor wireless connections (e.g., radio connections, optical or electricalconnections, etc.), wired or wireless networks (e.g., a Local AreaNetwork (LAN), a Wide Area Network (WAN), a private network, a publicnetwork (such as the Internet), a peer-to-peer network, a cellularnetwork, a Wi-Fi network, etc.), other physical connections (e.g.,pneumatic tubing, acoustic media, etc.) and others. In some cases, thefirst and second entities 1402, 1404 communicate with each otherindirectly, for example, through access to a shared database or otherresources, through an intermediate entity, through an escrow channel orotherwise. In some implementations, using the unique code at 1418 doesnot require the second entity 1404 to communicate with the first entity1402 or any other entity. For instance, the unique code can be used in aprocess (e.g., a security process or another type of process) that isexecuted internally by the second entity 1404.

In some implementations, the unique code is used in an authenticationprocess. For instance, the second entity 1404 may execute the operationsof the requester 1602 in the example process 1600 shown in FIG. 16. Insome cases, the authentication process includes or is implemented as achallenge-response process, such as, for instance, the examplechallenge-response process 1700 shown in FIG. 17. An authenticationprocess can be used for anti-counterfeiting, integrity verification,identity verification, chain of custody verification or another purpose.The authentication process can produce an output that indicates theauthenticity of the object, for example, as a binary (“pass” or “fail”)or as a graded value (e.g., as a percentage, likelihood or probability).

For anti-counterfeiting, the unique code can be used to authenticate theobject, for instance, to determine whether a purported source, grade,type or quality of the object is genuine (i.e., authentic) orcounterfeit (i.e., inauthentic). A product manufacturer may authenticatea product component, for example, to determine whether the productcomponent was manufactured by a particular component manufacturer. Aretailer may authenticate a branded product, for example, to determinewhether the branded product was produced by the indicated brand sourceor an authorized manufacturer. A bank may authenticate a currency item,for example, to determine whether the currency item was issued by aparticular financial institution or government. Authentication processescan be used for other types of anti-counterfeiting.

For integrity verification, the unique code can be used to authenticatethe object, for instance, to determine whether the object has remainedintact (i.e., authentic) or has been compromised or tampered with (i.e.,inauthentic). A distributor or end user may authenticate a product, forexample, to determine whether a product seal was disturbed, a componentwas disassembled or replaced (e.g., if a mounting screw was disturbed)or the object was otherwise tampered with. A pharmacy may authenticate acompound, for example, to determine whether a packaging or container hasbeen tampered with. Authentication processes can be used for other typesof integrity verification.

For identity verification, the unique code can be used to authenticatethe object, for instance, to determine whether the object is associatedwith a particular identity or identifier of a person or other entity(e.g., corporate entity, government entity, etc.). A hospital mayauthenticate a prescription drug container, for example, to determinewhether the contents are associated with a particular prescription orpatient. A healthcare provider may authenticate a prosthetic device orimplant, for example, to determine whether the device or implant isassociated with a particular patient or procedure. Authenticationprocesses can be used for other types of identity verification.

For chain of custody verification, the unique code can be used toauthenticate whether the object has been in possession of one or moreentities. A corporate entity may verify chain of custody of sensitiveproducts or information, for instance, to ensure confidentiality beforedeploying in a secure internal process. Law enforcement entities mayverify chain of custody of physical evidence, for instance, to ensureintegrity of an investigation. Authentication processes can be used forother types of chain of custody verification.

The authentication process may produce a result that the second entity1404 can act on. As an example, if the authentication process indicatesthat the object is authentic (e.g., with a binary indicator, with agrading above an acceptable threshold, etc.), then the second entity1404 may accept and deploy the object. For instance, a component may beinstalled, a drug may be administered, a financial instrument may beaccepted as payment, etc. As another example, if the authenticationprocess indicates that the object is inauthentic (e.g., with a binaryindicator, with a grading below an acceptable threshold, etc.), then thesecond entity 1404 may reject or quarantine the object. For instance, acomponent may be returned, a drug may be disposed, a financialinstrument may be declined as payment, etc.

In some implementations, the unique code is used in cryptographicprocess. For instance, a key (e.g., a private key, a shared secret,etc.) or another value for a cryptographic process may be generatedbased on the unique code (e.g., the unique code may be used as or usedto derive the key). The unique code can be used for messageauthentication (e.g., signing, verifying), message encryption (e.g.,encrypting, decrypting), key derivation (e.g., producing session keys,ephemeral keys, etc.) and other cryptographic applications.

In some implementations, the first and second entities 1402, 1404 canuse the unique code as a shared secret, for example, similar to the typeof shared secret produced by a cryptographic key agreement algorithm(e.g., Diffie-Hellman, quantum key distribution (QKD), or anotheralgorithm). The second entity 1404 may use the shared secret in anencrypted communication session over a public channel, for instance, toencrypt messages to the first entity 1402 or to decrypt messages fromthe first entity 1402. The second entity 1404 may use the shared secretin an authenticated communication session over a public channel, forinstance, to sign messages to the first entity 1402 or to verifymessages from the first entity 1402.

In some implementations, the second entity 1404 can use the unique codeas a private key and generate a related public key, for example, for usein a public key infrastructure (PKI) system. For example, the secondentity 1404 can use the private key to decrypt messages that have beenencrypted by another entity using the public key. As another example,another entity can use the public key to verify messages that have beensigned by the second entity 1404 using the private key. Example PKIsystems include RSA-based systems, elliptic curve systems, and others.

In some implementations, the object is used as (or in connection with) aledger (e.g., a secure ledger, a public ledger, a distributed ledger oranother type of ledger), and the unique code is used as (or is used togenerate) an entry or update in the ledger. For instance, a first uniquecode obtained (at 1412) by the first entity 1402 may represent a firstentry in the ledger, and a second, different unique code obtained (at1416) by the second entity 1404 may represent a second, different entryin the ledger. In some cases, the second entity 1404 modifies the objectbefore obtaining the unique code at 1416, which causes the second entity1404 to obtain the second, different unique code at 1416. For instance,the second entity 1404 may change the orientations of one or more of theelements of the object, so that orientation information extracted fromthe object produces a different unique code.

At 1420, the third entity 1406 obtains the object. The third entity 1406may obtain the object directly from the second entity 1404 or indirectlythrough one or more intermediary entities.

At 1422, the third entity 1406 obtains a unique code from the elementsof the object. The third entity 1406 can obtain the unique code, forexample, according to the example process 1500 shown in FIG. 15 oranother type of process. In some implementations, the third entity 1406obtains the unique code using the same process that the first entity1402 or the second entity 1404 (or both) used to obtain the unique code.In some instances, the first, second and third entities 1402, 1404 and1406 obtain the same unique code at 1412, 1416 and 1422, respectively.For example, when the elements of the object have not been altered, andan extraction protocol is executed properly, the unique code obtained bythe third entity 1406 (at 1422) may be identical to the unique codeobtained by the first entity 1402 (at 1412) and the second entity 1404(at 1416). In some instances, one or more of the first, second and thirdentities obtains a different unique codes from the other entities.

At 1424, the third entity 1406 uses the unique code. The third entity1406 (at 1424) may use the unique code obtained at 1422 in a manner thatis analogous to how the second entity 1404 (at 1418) uses the uniquecode obtained at 1416. In some implementations, the third entity 1406communicates with the first entity 1402 or the second entity 1404 (oranother entity) to use the unique code at 1424. For example, anauthentication process may be executed between the third entity 1406 andthe first entity; the authentication process may be executed directlybetween the third entity 1406 and the first entity 1402 or through anintermediate entity (e.g., the second entity 1404 or another entity). Insome cases, the process 1400 extends to additional entities in a similarmanner.

FIG. 15 is a flow diagram schematically illustrating an example process1500 for generating a unique code for an object. The example process1500 may include additional or different operations, and the operationsmay be performed in the order shown or in another order. In some cases,operations can be combined, performed in parallel, iterated or otherwiserepeated or performed in another manner.

In some cases, one or more of the operations shown in FIG. 15 areimplemented by a scanner system such as, for example, the scanner shownin FIG. 4 or another type of scanner system. The scanner system can beconfigured to extract information from a sample, for example, byapplying a stimulus to the sample and recording the sample's response tothe stimulus. The scanner system can include one or more probes thatapply the stimulus or record the sample's response (or both). Forinstance, the scanner system may include an illumination source (e.g., alaser or other light source), optical components (e.g., lenses, mirrors,filters, amplifiers, etc.), optical sensors, cameras (e.g., a CMOScamera, a CCD camera or another type of camera), signal generators(e.g., RF signal generators, microwave signal generators, etc.), coilsand antennas, magnet systems (e.g., an electromagnet, a superconductingmagnet, etc.) and other components, which may be arranged according tothe example shown in FIG. 14 or otherwise.

In examples where the scanner system is configured to inspect colorcenters of diamond particles, the scanner system includes one or moreprobes configured to obtain fluorescence images of the sample, forinstance, by applying illumination to the sample and detecting theobject's fluorescence response (e.g., over a range of applied staticmagnetic fields, applied static electric fields, etc.). In someexamples, the scanner system also includes one or more probes configuredto obtain magnetic resonance properties of the sample, for instance, bypositioning the sample in an external magnetic field, applying radio ormicrowave pulses to the sample and detecting the object's response tothe pulses. In some examples, the scanner system also includes a sampleregion where samples reside when they are inspected by the scannersystem.

In some cases, one or more of the operations shown in FIG. 15 areimplemented by a computer system. For example, the scanner system thatextracts information from the sample may include a processer thatanalyzes the extracted information. Additionally or alternatively,operations may be performed by another computer system. For example,information extracted by a scanner system can be communicated to aseparate computer system that is distinct (and in some cases, remote)from the scanner system.

At 1502, an object is received. The object can be received, for example,in a sample region of the scanner system. The object received at 1502 isa physical object that includes elements, for example, elementsintegrated into the structure of the object or otherwise distributed inthe object. The object received at 1502 can be of the type referred toin the process 1400 in FIG. 14. For example, the object can be orinclude a unique marker (UM) or another item that includes a suspensionof elements.

In some implementations, the object is a manufactured system or device(e.g., a container, a document, a medical device, etc.). In someimplementations, the object is a component of a manufactured system ordevice. For instance, the object can be a component (e.g., a label, lid,seal or other component) of a container (e.g., a prescription drugcontainer, a biological sample container, an envelope or other documentcontainer, a freight container, etc.), a printed area on a document(e.g., currency, bank note, or other commercial document), a part of amedical device (e.g., a prosthetic device or implant), a tag affixed toa retail good or electronic device, etc.

In some implementations, the object is a macroscopic object and theelements are microstructures or nanostructures of the object. Forexample, the elements can be diamond particles, magnetic particles,nanorods, microstructures such as flakes or foils, molecules exhibitingelectron paramagnetism, molecules with finite electric dipole moments,or other types of structures suspended in the object. The object canhave a macroscopic size, for example, having a largest dimension on theorder of millimeters, centimeters, or larger; and the elements can havesizes that are one or more orders of magnitude smaller than the object,for example, elements having largest dimensions on the order ofmillimeters, micrometers or nanometers in some cases. In some examples,the elements are crystalline particles fixed in a medium. Thecrystalline particles can be, for instance, diamond particles havingrespective color centers (e.g., NV centers or other types of colorcenters), and the medium can be an organic or inorganic material. Insome cases, crystalline particles can be suspended in silicon, glass,thermoplastics (e.g., acrylic, Acrylonitrile butadiene styrene (ABS),Polyvinyl chloride (PVC), polyethylene), thermosetting polymers (e.g.,epoxies and polyurethanes) or other types of material. The object mayinclude hundreds, thousands, millions or more elements. The elements maybe dispersed throughout all or part of a volume of the object, dispersedover all or part of a surface of the object or otherwise distributed inthe object.

In some implementations, each element has a structure (internal orexternal) that defines an orientation of the element. For example, anelement may have a crystalline structure, and the orientation of theelement may be defined by a particular axis (e.g., a symmetry axis) orplane of the element's crystalline structure. As another example, anelement may have an elongate structure, and the orientation of theelement may be defined by a particular axis (e.g., the long axis) orplane of the element's elongate shape. As another example, an elementmay have an internal feature or structure (e.g., a color center), andthe orientation of the element may be defined by a particular axis(e.g., the NV axis) or plane of the internal feature or structure of theelement.

In some implementations, each element is fixed in the object relative tothe other elements in the object. For instance, the elements may besecured in the object such that their relative locations andorientations remain fixed as long as the shape and structure of theobject remains fixed. Accordingly, the object may inherently define adistribution of element properties that can be detected, in a repeatableand deterministic manner, by detecting the individual elements. Forinstance, the suspension of elements may define a distribution ofrelative spatial orientations, a distribution of relative locations, adistribution of sizes and shapes, etc. The distribution of elementproperties may have thousands, millions or more independent degrees offreedom that can vary in each object.

In some implementations, some or all of the element properties arecontrolled by a highly complex, random or quasi-random process, forinstance, a thermodynamic process that occurs when the object ismanufactured. Accordingly, the distribution of element properties in anindividual object may be difficult or impractical (or even impossible)to clone or duplicate in another object. Thus, the distribution ofelement properties can be unique for each individual object, and mayserve as a unique identifier of the object, akin to a fingerprint orsignature.

At 1504, element information is extracted from the object. The elementinformation can be extracted from the object, for example, by operationof one or more probes of the scanner system. The element information caninclude, or it can be based on, the distribution of element propertiesdefined by the elements of the object. For instance, the elementinformation can describe a distribution of relative spatialorientations, a distribution of relative locations, a distribution ofsizes and shapes, or combinations of these.

In some cases, the element information is extracted by imaging theobject using optical microscopy (e.g., as described with respect to FIG.4) and processing the resulting images. In some cases, the elementinformation is extracted by detecting magnetic resonance properties ofthe object (e.g., as described with respect to FIG. 4) and processingthe magnetic resonance data.

In some cases, the element information is extracted by an extractionprotocol performed by the scanner system, and the element informationmay depend on the element properties and the parameters of theextraction protocol. For instance, the parameters of the extractionprotocol may be provided as inputs to a controller or control process(e.g., the main logic module 408 in FIG. 4) that operates the probe(s)of the scanner system. In some cases, the element information extractedfrom the object does not necessarily depend on the parameters of theextraction protocol. For example, two distinct extraction protocols thatidentify the orientations of the same elements (e.g., all the elements,or the same subset of elements) may produce the same orientationinformation, since the orientations are fixed. And the elementinformation can be defined in a standardized or pre-defined format,which may be invariant under global rotations of the objects.

In some implementations, extracting the element information includesextracting orientation information from the object, where theorientation information indicates relative spatial orientations of therespective elements of the object. The orientation information can beformatted as a list, an array or another format. In some cases, theorientation information includes coordinate transformations describingthe relative spatial orientations of the respective elements. Thecoordinate transformations can be, for example, a list of transformationmatrices, an order set of orthogonal rotations (such as an Eulerdecomposition) or coordinate transformations in another form. Inexamples where the elements are diamond particles, the orientationinformation can be a list of a composite transformation matrices (e.g. acomposite transformation matrix for each diamond particle), and the listof composite transformation matrices can be invariant to globalrotations of the coordinate system of the object.

In some cases, the orientation information and possibly other elementinformation (e.g., location information, size information, shapeinformation) is extracted by obtaining an optical response (e.g. afluorescence response or another type of optical response) toillumination applied to the object. The optical response may includeRaman scattering or another nonlinear effect (e.g., second harmonicgeneration, spontaneous parametric down conversion, etc.) in some cases.In some examples, a fluorescence response can include electromagneticsignals, for example, in the range of 635 nm-800 nm or anotherwavelength, produced by a color center or another feature of an element(e.g., stokes and anti-stokes shifts or another nonlinear process).Fluorescence images of the object can be generated based on thefluorescence responses of the elements, and the relative spatialorientations can be determined from the fluorescence images. The image500 shown in FIG. 5 represents an example of a monochrome fluorescenceimage with 1-bit color depth. The orientation information may bedetermined based on fluorescence changes in the object, for example,fluorescence changes of the elements detected in response to changes inthe illumination or changes in a field applied to the object. In anotherexample, the orientation information can be determined based on theorientation dependence of a nonlinear optical process (e.g., secondharmonic generation (SHG)).

In some cases, the orientation information and possibly other elementinformation (e.g., magnetic environment information) is extracted usingmagnetic resonance techniques such as, for example, electron spinresonance (ESR), nuclear magnetic resonance (NMR), optically detectedmagnetic resonance (ODMR) or another type of magnetic resonancetechnique. For example, a scanner can obtain a magnetic resonanceresponse to an oscillatory electromagnetic field (e.g., radio frequency,microwave frequency, etc.) applied to the object, and a computer systemcan determine the relative spatial orientations by analyzing themagnetic resonance responses. The magnetic resonance response can beobtained, for example, by positioning the object in an external magneticfield (e.g., a static external field), applying the oscillatoryelectromagnetic field (e.g., applying radio or microwave frequencypulses) to the object in the external magnetic field, and opticallydetecting magnetic resonance changes of the elements in response torelative changes in the external magnetic field (e.g., relative changesin the strength or orientation of the external magnetic field), relativechanges in the oscillatory electromagnetic field (e.g., relative changesin the amplitude, frequency, or phase the oscillatory electromagneticfield).

In some implementations, the orientation information can be extractedindependent of registering the object, for example, relative to thescanner system. In some cases, the object does not include registrationmarkings or orientation references other than the elements themselves.When the orientation information is extracted by applying illuminationto the object, the orientations of the elements can be describedrelative to each other, without reference to the angle of illumination.Similarly, when the orientation information is extracted by magneticresonance techniques, the orientations of the elements can be describedrelative to each other, without reference to the angle of an appliedmagnetic field. Accordingly, the orientation information can beinvariant to global rotations of the coordinate system of the object.

When the crystalline particles are diamond particles that haverespective color centers, the orientation information can be extractedby detecting relative orientations of the color centers. Relativeorientations can be detected, in some cases, by processing fluorescenceimages, magnetic resonance data or other measurements of the object. Forexample, the relative orientations can be identified using coordinatetransformations, for instance, a composite transformation matrix thatrepresents multiple transformations for each diamond particle (e.g., asdescribed with respect to FIGS. 6 and 7). A composite transformationmatrix for a diamond particle can represent a first transformationbetween a coordinate system of the object and a coordinate system of thediamond particle, and a second transformation between the coordinatesystem of the diamond particle and a coordinate system of a color centerin the diamond particle. In some examples, each diamond particleincludes a single color center (e.g., each individual diamond particlecontains a single NV center). In some examples, some or all of thediamond particles include multiple color centers (e.g., each individualdiamond particle contains two or more NV centers). When a single diamondcrystal includes multiple NV centers, the four-fold symmetry of thediamond lattice means that any of the four orientations can be chosen asa reference to describe the orientation of the particle.

In some implementations, extracting the element information includesextracting location information from the object, where the locationinformation indicates relative spatial positions of the respectiveelements of the object. The location information can be formatted as alist, an array or another format. In some cases, the locationinformation includes a list of coordinate vectors describing therelative spatial positions of the respective elements. Relativelocations can be detected, in some cases, by processing fluorescenceimages, magnetic resonance data or other measurements of the object. Forexample, the relative locations can be identified using as describedwith respect to FIG. 5 or in another manner.

In some implementations, extracting the element information includesextracting topographical information from the object, where thetopographical information indicates relative spatial topographies (e.g.,relative sizes, relative shapes, etc.) of the respective elements of theobject. The topographical information can be formatted as a list, anarray or another format. In some cases, the topographical informationincludes a list of coordinate vectors describing the dimensions (e.g.,along one or more coordinate axes). The topographies of the elements canbe detected, in some cases, by processing fluorescence images, magneticresonance data or other measurements of the object.

In some implementations, extracting the element information includesextracting magnetic environment information from the object, where themagnetic environment information indicates the magnetic environments ofthe respective elements of the object. The magnetic environmentinformation can be formatted as a list, an array or another format. Insome cases, the magnetic environment information includes a list ofcoordinate vectors describing the magnetic field strength (e.g., alongone or more coordinate axes) experienced by each element. The magneticenvironment of the elements can be detected, in some cases, byprocessing magnetic resonance data or other measurements of the object.

The element information may indicate the properties of the elements, forexample, in two or three spatial dimensions. For example, theorientation information may indicate the relative spatial orientationsin a two-dimensional space or a three-dimensional space; likewise, thetopographical and location information may indicate the relativelocations, sizes, shapes, etc. in a two-dimensional space or athree-dimensional space. In examples where the elements are crystallineparticles fixed in another medium of the object, the element informationcan indicate the relative sizes, shapes, orientations, or positions ofthe crystalline particles, or combinations of these properties, forexample, in two or three spatial dimensions.

At 1506, a unique code is generated from the element information. Theunique code may be generated, for example, by a processor in the scannersystem, by a computer system that is separate from the scanner system,or a combination of them. For example, another computer system mayobtain the element information (orientation information, locationinformation, topographical information, magnetic environment informationor combinations of these) and generate the unique code.

In some implementations, the unique code is generated from orientationinformation that a scanner system extracted from the object, and theunique code does not depend on any registration or relative orientationbetween the object and the scanner system. For instance, the orientationinformation may be processed independent of the relative orientationbetween the object and the scanner system. When the orientationinformation is extracted by applying illumination to the object, theunique code may be determined without reference to the angle at whichthe illumination is applied to the object. Similarly, when theorientation information is extracted by magnetic resonance techniques,the unique code may be determined without reference to the angle atwhich the external (static or oscillatory) magnetic field is applied tothe object.

In some implementations, the unique code is generated from elementinformation representing only a subset of the elements in the object.For example, the object may include a superset of elements, and theelement information that is used to generate the unique code mayrepresent only a subset of the elements (less than all the elements).

In some cases, the element information extracted at 1504 indicateproperties of only the subset of elements, and the unique code isgenerated at 1506 from all of the element information extracted at 1504.For instance, the subset of elements could be the elements that respondto a stimulus in a particular range of field strength, frequency,polarization, etc. As an example, when the elements are diamondparticles, a camera may be used to observe only the diamond particleswith an optical response to a specific frequency band, for example, 2.77to 2.79 Gigahertz (GHz) or another frequency band.

In some cases, the element information extracted at 1504 indicateproperties of all elements in the superset, and the unique code isgenerated at 1506 from a subset of the element information extracted at1504. For instance, a subset of orientation information, which indicatesrelative spatial orientations of the subset of the elements, may beidentified from the full set of element information, so that the uniquecode can be generated based on the relative spatial orientations of onlythe subset. The subset of elements could be the elements in a particularregion of the object, the elements that produce a particular signalstrength, or another subset of elements.

The unique code can include information in any suitable form or format,and may be generated by processing the element information in anysuitable manner. For example, the unique code can be binary oralphanumeric, or it may include other types of symbols or values. Theunique code may be formatted as a single value or a collection (e.g., alist, an array, etc.) of values or another format. As an example, whenthe orientation information includes a list of coordinatetransformations, the list may be processed or reformatted to define theunique code. In some cases, a function or transformation is applied tothe element information to generate the unique code.

In the example process 1500, the unique code generated at 1506 is uniqueto the object. For instance, the unique code may be defined byparameters in a phase space that is sufficiently large that no twoobjects would produce the same code, in a practical sense. The size ofthe phase space can be defined, for example, by the number degrees offreedom in the element information extracted from the object. Thelikelihood that another object (manufactured by the same process, usingthe same materials, etc.) would occupy the same position in phase spacemay be infinitesimally small. In some cases, it would be impractical toproduce another object that would produce the same would occupy the sameposition in phase space and produce the same code.

At 1508, the object may be modified. For example, modifying the objectmay change the relative spatial orientations or spatial locations (orboth) of at least some of the elements. The process 1500 may berepeated, for example, after modifying the object 1508 or at otherinstances. In some cases, on a first iteration of the process 1500, afirst unique code for the object is generated; on a second iteration ofthe process 1500, a second, different unique code is generated for thesame object based on orientation information extracted from the objectafter changing the relative spatial orientations. In some cases,relative spatial orientations of the elements can be used as a secure orpublic ledger for information related to the object. For example,changing the spatial orientations (by modifying the object at 1508) canbe associated with an update to the ledger.

FIG. 16 is a flow diagram schematically illustrating an example process1600 for analyzing an object. The example process 1600 may includeadditional or different operations, including operations performed byadditional or different entities, and the operations may be performed inthe order shown or in another order. In some cases, operations can becombined, performed in parallel, iterated or otherwise repeated orperformed in another manner. The example process 1600 can be used toauthenticate the identity of the object, determine whether the objecthas been tampered with, determine whether the object has been used oractivated, determine whether the object has been exposed toenvironmental stress, determine whether the object has been subjected tomechanical stress or wear, or other types of analysis of the object.

In some cases, operations shown in FIG. 16 are implemented by one ormore computer systems. FIG. 16 shows the example process 1600 performedby a requester 1602 and an authenticator 1604. The requester 1602 andauthenticator 1604 may represent computer-implemented modules deployed,for example, in a single computer system, in distinct computer systems(e.g., at disparate locations, in disparate environments, etc.), in adistributed computing system, or in processes of distinct entities(e.g., in a manufacturing process, an industrial process, a supplychain, a distribution channel, a financial process, a corporate workflowor another type of process). As an example, the requester 1602 mayrepresent a process executed at the destination 1300 in FIG. 13, and theauthenticator 1604 may represent a process executed at the authenticator1350 in FIG. 13. As another example, the requester 1602 may represent aprocess executed at the second entity 1404 in FIG. 14, and theauthenticator 1604 may represent a process executed at the first entity1402 in FIG. 14.

The requester 1602 and authenticator 1604 communicate with each otherduring the process 1600. In some implementations, the requester 1602 andauthenticator 1604 communicate with each other directly, for example,over a communication channel or a direct communication link. In someimplementations, the requester 1602 and authenticator 1604 communicatewith each other indirectly, for example, through access to a shareddatabase or otherwise.

The example process 1600 shown in FIG. 16 utilizes information extractedfrom a physical object. In some cases, the object referred to in theexample process 1600 in FIG. 16 can be or include a unique marker (UM)of the types described above, an object of the type referred to in theprocess 1400 in FIG. 14, an object of the type referred to in theprocess 1500 in FIG. 15 or another type of object. In someimplementations, the extracted information includes element informationindicating properties of respective elements of the object (e.g.,orientation information indicating relative spatial orientations of therespective elements).

The example process 1600 may also utilize an object identifier andpotentially other information related to the physical object. The objectidentifier can be, for example, a serial number of the object, a partnumber of the object, or an identity of a source, grade, type or qualityof the object. The object identifier can be, for example, an identity oridentifier for a person or other entity (e.g., name, address, phonenumber, username, social security number, etc.) associated with theobject.

Before or during the process 1600, a unique code is generated fromelement information extracted from the object, and the unique code isassociated with an object identifier for the object. The unique code maybe generated in the same manner that the unique code is generated in theprocess 1500 shown in FIG. 15. The object identifier and the unique codecan be associated, for example by storing them in a secure database orin another manner. For instance, the object identifier can be the serialnumber 1207 in FIG. 12, the element information can be the orientationinformation 1206 in FIG. 12, and the object identifier and elementinformation can be associated by linking them in the secure data storage1208 in FIG. 12 (or the secure database 1351 in FIG. 13). The objectidentifier and unique code may be associated in another manner.

In some implementations, additional information is stored in the securedatabase or otherwise associated with the object identifier and theunique code. For example, scanner settings used by a scanner system toextract the element information can be associated with the objectidentifier and the unique code. The scanner settings may include, forexample, values of parameters used in an extraction protocol performedon the object.

At 1610, the requester 1602 obtains object data. For example, the objectdata may include a unique code based on element information that therequester 1602 extracted from the object. The unique code can be orinclude, for example, a unique code generated by the requester 1602 fromelement information, as in the process 1500 shown in FIG. 15 or inanother manner. The object data obtained at 1610 may also include anobject identifier such as, for example, a serial number of the object.The object data obtained at 1610 may also include challenge-responsedata or other types of information.

At 1612, the requester 1602 sends an analysis request to theauthentication provider. The analysis request may include or be based onthe object data including, for example, the unique code and the objectidentifier. In some cases, the analysis request includes additionalinformation. For example, the analysis request may indicate scannersettings used by a scanner system of the requester 1602 to extract theelement information.

At 1614, the authenticator 1604 evaluates the analysis request. Theauthentication request can be evaluated based on information in a securedatabase or another type of secured system that is accessible to theauthenticator 1604. As an example, the authenticator 1604 may use theobject identifier (and in some cases, other information such as, forexample, scanner settings, etc.) from the analysis request to find avalid unique code that was previously associated with the objectidentifier. The authenticator 1604 may then compare the valid uniquecode with the proffered unique code in the analysis request.

At 1616, the authenticator 1604 sends an analysis response to therequester 1602. The analysis response in FIG. 16 includes analysis data,which indicate a result of the evaluation performed at 1614. Theanalysis response may indicate the result as a binary value. Forexample, the analysis data may indicate that the comparison yielded amatch (e.g., the valid unique code in the database matches the profferedunique code in the analysis request exactly or within some tolerance),which may mean that the object is authentic, has not been tampered with,has not been used or activated, has not been exposed to environmentalstress, has not been subjected to mechanical stress or wear, etc.; orthe analysis data may indicate that the comparison did not yield a match(e.g., the valid unique code in the database does not match theproffered unique code in the analysis request exactly or within sometolerance), which may mean that the object is inauthentic, has beentampered with, has been used or activated, has been exposed toenvironmental stress, has been subjected to mechanical stress or wear,etc. The analysis response may indicate the result as a graded value.For example, the analysis data may indicate a percentage or degree towhich the valid unique code matches the proffered unique code in theanalysis request, and the requester 1602 can interpret the graded valuebased on its own criteria (e.g., with reference to some tolerance orother acceptance criteria).

FIG. 17 is a flow diagram schematically illustrating an examplechallenge-response process 1700. The example process 1700 may includeadditional or different operations, including operations performed byadditional or different entities, and the operations may be performed inthe order shown or in another order. In some cases, operations can becombined, performed in parallel, iterated or otherwise repeated orperformed in another manner.

In some cases, operations shown in FIG. 17 are implemented by one ormore computer systems. FIG. 17 shows the example process 1700 performedby a requester 1702 and a validator 1704. The requester 1702 andvalidator 1704 may be implemented similar to the requester 1602 andauthenticator 1604 in FIG. 16, for example, as computer-implementedmodules in one or more computer systems. As an example, the requester1702 may represent a computer-implemented process executed at thedestination 1300 in FIG. 13, and the validator 1704 may represent acomputer-implemented process executed at the authenticator 1350 in FIG.13. As another example, the requester 1702 may represent a processexecuted at the second entity 1404 in FIG. 14, and the validator 1704may represent a process executed at the first entity 1402 in FIG. 14.The requester 1702 and validator 1704 communicate with each other(directly or indirectly) during the process 1700.

The example process 1700 shown in FIG. 17 utilizes information extractedfrom a physical object. In some cases, the object referred to in theexample process 1700 in FIG. 17 can be or include a unique marker (UM)of the types described above, an object of the type referred to in theprocess 1400 in FIG. 14, an object of the type referred to in theprocess 1500 in FIG. 15 or another type of object. In someimplementations, the extracted information includes element informationindicating properties of respective elements of the object (e.g.,orientation information indicating relative spatial orientations of therespective elements). The example process 1700 may also utilize anobject identifier and potentially other information related to thephysical object.

The challenge-response process 1700 may be executed as an analysisprocess (e.g., to authenticate the object, determine whether the objecthas been tampered with, determine whether the object has been used oractivated, determine whether the object has been exposed toenvironmental stress, determine whether the object has been subjected tomechanical stress or wear, etc.) or for other purposes. In some cases,the challenge-response process 1700 is used where the object is deployedas a physically unclonable function (PUF). For instance, when aparticular stimulus or challenge is applied to the object, the objectcan provide a predictable response that is unique to the object anddifficult or impractical (or even impossible) to obtain without theobject. The response to an individual challenge may depend, for example,on a highly-complex internal structure of the object, which is difficultor impractical (or even impossible) to duplicate or determineanalytically. Accordingly, the object, when deployed as a PUF, may servethe same purpose as a one-way function (e.g., a hash function) in someinstances.

At 1710, the requester 1702 obtains challenge data. For example, thechallenge data may indicate an extraction protocol that can be used by ascanner system of the requester 1702 to extract element information fromthe object. In some cases, the challenge data indicate scanner settingsfor an extraction protocol. The scanner settings may include, forexample, specific values for parameters of the scanner system to executethe extraction protocol. In some implementations, the requester 1702obtains the challenge data from the validator 1704 or another externalsource. In some implementations, the requester 1702 generates thechallenge data, for example, by randomly selecting scanner settings, byselecting a predefined set of scanner settings or otherwise.

At 1712, the requester 1702 obtains response data based on the challengedata. The response data may be obtained by interrogating the objectaccording to the challenge data, for instance, by executing anextraction protocol using scanner settings indicated by the challengedata. The response data may include a unique code generated from elementinformation that was extracted from the object using the challenge data.The element information may be extracted from the object as in theprocess 1500 shown in FIG. 15 or in another manner. The response dataobtained at 1712 may also include an object identifier such as, forexample, a serial number of the object.

At 1714, the requester 1702 sends response data to the validator 1704.In some cases, the requester 1702 also sends the challenge data to thevalidator 1704. The requester 1702 may also send an object identifier orother information to the validator 1704.

At 1716, the validator 1704 evaluates the response data. The responsedata can be evaluated based on information in a secure database oranother type of secured system that is accessible to the validator 1704.As an example, the validator 1704 may use the challenge data (and insome cases, other information such as, for example, an objectidentifier, etc.) to find a valid response that was previously obtainedfrom the object. The validator 1704 may then compare the valid response(e.g., from a secure database) with the proffered response in theresponse data.

In some cases, the validator 1704 uses a pre-defined valid response toevaluate the response data at 1716. For instance, the validator 1704 mayhave access to a challenge-response library for the object, where eachvalid response in the challenge-response library is associated with adistinct challenge. The challenge-response library may be defined beforethe challenge-response process 1700 is executed, for example, byinterrogating the object based on a set of distinct challenges or inanother manner. In some cases, the validator 1704 generates the validresponse during the challenge-response process 1700 based on thechallenge data obtained at 1710. For instance, the validator 1704 mayhave access to complete element information for the object, which mayenable the validator 1704 to compute a valid response based on thechallenge data.

At 1718, the validator 1704 sends validity data to the requester 1702.The validity data in FIG. 17 indicate a result of the evaluationperformed at 1716. The validity data may indicate the result as a binaryvalue. For example, the validity data may indicate that the comparisonyielded a match (e.g., the valid response in the database matches theproffered response in the response data exactly or within sometolerance), which may mean that the response is valid; or the validitydata may indicate that the comparison did not yield a match (e.g., thevalid response in the database does not match the proffered response inthe response data exactly or within some tolerance), which may mean thatthe response is invalid. The validity data may indicate the result as agraded value, for instance, as a percentage or degree to which the validresponse matches the proffered response, and the requester 1702 caninterpret the graded value based on its own criteria (e.g., withreference to some tolerance or other acceptance criteria).

In some implementations, the unique marker can be shaped to the surfacemorphology of the object. As an example, the unique marker 103 a shownin FIG. 1A, the unique marker 401 shown in FIG. 4, the unique marker1201 shown in FIG. 12, the unique marker 1303 shown in FIG. 13, or anyother unique marker, can be shaped to surface patterns, textures, orother indentations of the object or article.

FIGS. 18A and 18B are diagrams of an example object 1802 having anexample unique marker 1804 that is shaped to the surface morphology ofthe object 1802. Specifically, FIG. 18A is a view of the object 1802having the unique marker 1804 shaped to its surface morphology, and FIG.18B is an exploded view of the object 1802 and the unique marker 1804shown in FIG. 18A. In some implementations, the object 1802 can be thesneaker 101 shown in FIG. 1A, the article 1202 shown in FIG. 12, theunique article 1301 shown in FIG. 13, or any other object or article. Insome implementations, the unique marker 1804 can be the unique marker103 a shown in FIG. 1A, the unique marker 401 shown in FIG. 4, theunique marker 1201 shown in FIG. 12, the unique marker 1303 shown inFIG. 13, or any other unique marker. The example object 1802 and uniquemarker 1804 are shown schematically in FIGS. 18A and 18B and maygenerally have any size and shape.

As shown in FIG. 18B, a surface of the object 1802 may include anindentation 1803. In some cases, the object 1802 can be made of anysolid material (metal, plastic, wood, leather, etc.), and theindentation 1803 may be made, for example, via stamping, engraving,etching, or otherwise patterning the object 1802. In some examples, theindentation 1803 is made for a reason other than carrying the uniquemarker 1804. For example, the indentation 1803 can be a surface patternthat is produced by a manufacturing process, a natural texture ofmaterial, or otherwise. In some instances, surface patterning can beused for aesthetic or functional purposes on object 1802 and in themanufacture of the object 1802. In some examples, the indentation 1803is an aesthetic feature of a product, such as a decorative surfacetexture. In some examples, the indentation 1803 is a functional featureof a product, such as a company name, logo, or serial number embeddedinto the surface, or to provide structural benefits to the product (e.g.ribs or indents to protect from external wear). In some examples, theindentation 1803 is present for further manufacture. For instance, theindentation 1803 can include a patterned engraving on a cylindricalobject 1802 (which may be a first substrate) that is used to imprint aspecific pattern onto a second or third substrate (e.g., via arotogravure or flexography printing process) to mass produce tags ofuniform shape and size.

In some cases, the indentation 1803 can be used to host the uniquemarker 1804 that serves as a unique fingerprint for the object 1800. Forexample, in some implementations, the unique marker 1804 (e.g., an outersurface of the unique marker 1804) is sized and shaped to match the sizeand shape of the indentation 1803 (e.g., such that the unique marker1804 resides within the indentation 1803). In some implementations, theunique marker 1804 is formed in the indentation 1803, for instance, byfilling etches, grooves, cells, or surface patterns of the indentation1803 with a liquid material that dries to form the unique marker 1804,which may serve as a long term (e.g., permanent) fingerprint for theobject 1802.

FIG. 19A is a schematic diagram of an example object 1900 having anindented logo 1903, and FIGS. 19B, 19C, 19D, and 19E are illustrationsof an example process of forming a unique marker 1908 in the indentedlogo 1903. The object 1900 can be, for example, a commercial productthat includes the indented logo 1903 or another type of surfacemorphology. For example, in some implementations, the object 1900 can bethe sneaker 101 shown in FIG. 1A, the article 1202 shown in FIG. 12, theunique article 1301 shown in FIG. 13, the object 1802 shown in FIG. 18,or any other object or article. In some implementations, the indentedlogo 1903 may be the indentation 1803 shown in FIG. 18, and the uniquemarker 1908 can be the unique marker 103 a shown in FIG. 1A, the uniquemarker 401 shown in FIG. 4, the unique marker 1201 shown in FIG. 12, theunique marker 1303 shown in FIG. 13, the unique marker 1804 shown inFIG. 18, or any other unique marker.

FIGS. 19B, 19C, 19D, and 19E show cutaway cross-sectional views of aportion of the object 1900 having the indented logo 1903. Specifically,FIGS. 19B, 19C, 19D, and 19E show cutaway cross-sectional views along aline A-A shown in FIG. 19A. As seen in FIG. 19B, the object 1900includes a substrate 1902 that is patterned to form the indented logo1903. In some implementations, the indented logo 1903 may be formed viastamping, engraving, etching, or otherwise patterning the substrate1902.

In FIG. 19C, a fluid 1904 (e.g., a liquid or viscous fluid) containing adistribution of elements 1905 (e.g., crystalline particles or othertypes of elements) is applied to the substrate 1902 to fill (e.g.,overfill) the indented logo 1903. The concentration of the elements 1905in the fluid 1904 may depend, at least in part, on the element size andthe size of the unique marker that is being formed. The elements 1905may be distributed within the fluid 1904 so that their spatialdistribution and relative orientations within the fluid 1904 is not setuntil the fluid 1904 has solidified.

The fluid 1904 can be a liquid resin or another type of liquid material.For instance, the fluid 1904 may be or include a resin, epoxy, acrylic,urethane, silicone, or another liquid resin. In some cases, the resinmay be mixed with a solvent (e.g., xylene, toluene, ethyl acetate),inks, and other elements such as silica for additionalfunctionalization. In some implementations, the fluid 1904 can beapplied to the substrate 1902 by an application process (e.g., pouring,dipping, rolling, printing, painting, dropping, coating, spraying,spreading, brushing, etc. onto the substrate 1902). The fluid 1904 maybe applied by any suitable process (e.g., manually, via automatedmechanical processes, etc.).

In FIG. 19D, the excess material of the fluid 1904 is removed from thesurface of the substrate 1902 using a planarizing process. In someinstances, such as in the example of FIG. 19D, the planarizing processmay use a removal instrument 1906 to remove the excess material of thefluid 1904 from the surface of the substrate 1902. In someimplementations, the removal instrument 1906 may be or include, forexample, doctor blades, spatulas, squeegees, or another type of removalinstrument 1906. Specifically, excess material 1907 of the fluid 1904from the non-indented portions of the substrate 1902 are removed suchthat the surfaces of the substrate 1902 and the fluid 1904 within theindented logo 1903 are substantially co-planar. In some instances, ascraping process may be used to remove the excess material 1907 of thefluid 1904. The removed excess material 1907 of the fluid 1904 may bere-used or disposed of.

In FIG. 19E, the fluid 1904 that remains within the indented logo 1903is subjected to a process (e.g. a hardening process) that causes thefluid 1904 to harden and solidify, thus forming the unique marker 1908having elements 1905 whose spatial distribution and relativeorientations are set. The fluid 1904 may solidify, for example, byordinary drying, curing, by exposure to an energy source (e.g. UVradiation), or another process that causes the fluid 1904 to harden andsolidify.

The unique marker 1908 can be used as a decorative feature in somecases, and may be used for authentication, security, verifying theintegrity of the object 1900, and other applications. For example, aunique code can be extracted based on the spatial distribution andrelative orientations of the elements 1905, for example, according tothe example processes 1400, 1500 shown in FIGS. 14 and 15, or anothertype of process. In some implementations, the unique marker 1908 has aunique set of features that allow secondary identification that can bederived using other tools (e.g. spectrometry via with functionalizedfluorescent particles, NMR via measuring nuclear spins, dynamic lightscattering (DLS) through a particular particle size distribution),allowing batch-, lot-, or brand-level information to be extracted.

Although the example shown in FIGS. 19B, 19C, 19D, and 19E show that thefluid 1904 is applied after creating the indented logo 1903, in someimplementations, the fluid 1904 may be applied to the substrate 1902 bythe same process that creates the indented logo 1903. For example, thefluid 1904 may be applied by coating a die or stamp head the fluid 1904(containing the elements 1905) before impressing the die or stamp headinto the substrate 1902 to form the indented logo 1903.

FIG. 20A is a schematic diagram of an example flexography printingsystem 2000. The example flexography printing system 2000 can be used toform a unique marker that is shaped to the surface morphology of anobject. The flexography printing system 2000 includes a fountain 2002.In some implementations, the fountain 2002 is a container that containsa fluid (e.g., a liquid or viscous fluid) 2004 containing a distributionof elements (e.g., crystalline particles or other types of elements)that is used to form the unique marker. The fluid 2004 may be similar tothe fluid 1904 described above in relation to FIGS. 19C, 19D, 19E.

The flexography printing system 2000 includes a first cylindricalstructure 2006 (e.g., a fountain roller) that is at least partiallysubmerged in the fluid 2004. In some implementations, the firstcylindrical structure 2006 may be a metal (e.g., steel or copper)cylinder, although other materials (e.g., ceramics) can also be used.During operation of the flexography printing system 2000, the firstcylindrical structure 2006 rotates in a first direction (e.g., acounterclockwise direction in the example of FIG. 20A) so that, as thefirst cylindrical structure 2006 rotates, the fluid 2004 coats theportion of the first cylindrical structure 2006 that is not submerged inthe fluid 2004.

The flexography printing system 2000 includes a second cylindricalstructure 2008 (e.g., an anilox roller) that is used as a carrier forthe fluid 2004. In some implementations, the second cylindricalstructure 2008 may be a metal (e.g., steel or copper) cylinder, althoughother materials (e.g., ceramics) can also be used. In someimplementations, the outer surface of the second cylindrical structure2008 includes patterned or etched cells, channels, or other depressedfeatures that function as carriers for the fluid 2004 (and hence thedistribution of elements contained in the fluid 2004). During operationof the flexography printing system 2000, the second cylindricalstructure 2008 rotates in a second, different direction (e.g., aclockwise direction in the example of FIG. 20A), and the fluid 2004 fromthe first cylindrical structure 2006 fills the etched cells that areformed on the surface of the second cylindrical structure 2008. In someimplementations, the flexography printing system 2000 includes anoptional removal instrument 2010 (e.g., a doctor blade) that removesexcess material of the fluid 2004 from the etches cells that are formedon the surface of the second cylindrical structure 2008.

The flexography printing system 2000 includes a third cylindricalstructure 2012 (e.g., a plate cylinder) that holds a printing plate 2014(e.g., a flexo plate). In some implementations, the third cylindricalstructure 2012 may be a metal (e.g., steel or copper) cylinder, althoughother materials (e.g., ceramics) can also be used. The printing plate2014 may be made from a soft flexible rubber-like material. In someimplementations, tapes, magnets, tension straps, ratchets, or acombination of these, may be used to hold the printing plate 2014against the third cylindrical structure 2012. During operation of theflexography printing system 2000, the third cylindrical structure 2012rotates in the first direction (e.g., a counter-clockwise direction inthe example of FIG. 20A), and the fluid 2014 in the etched cells of thesecond cylindrical structure 2008 are transferred to the printing plate2014.

The flexography printing system 2000 includes a fourth cylindricalstructure 2016 (e.g., an impression cylinder). In some implementations,the fourth cylindrical structure 2016 may be a metal (e.g., steel orcopper) cylinder, although other materials (e.g., ceramics) can also beused. During operation of the flexography printing system 2000, asubstrate 2018 (e.g., metal, plastic, wood, leather, etc.) is placedbetween the fourth cylindrical structure 2016 and the third cylindricalstructure 2012. The fourth cylindrical structure 2016 applies pressureto the third cylindrical structure 2012 and the rotates in the seconddirection (e.g., a clockwise direction in the example of FIG. 20A),thereby imprinting the substrate 2018 with an indentation andtransferring the fluid 2004 to the substrate 2018 such that the fluid2004 conforms with the morphology of the indentation. In some instances,the substrate 2018 having the fluid 2004 may be cured (e.g., by ordinarydrying, exposure to an energy source such as UV radiation, or anotherprocess) to set the spatial distribution and relative orientations ofthe elements in the fluid 2004 and form the unique marker. In someimplementations, the flexography printing system 2000 can be used tocreate numerous, patterned unique markers in or on the substrate 2018alongside untagged areas that are printed normally. The substrate 2018having the unique marker can subsequently be used to manufacture theproduct or article.

As discussed above, the outer surface of the second cylindricalstructure 2008 includes etched cells that function as carriers for thefluid 2004. FIG. 20A also shows a zoomed-in top-down view of some cells2020 that are etched into the outer surface second cylindrical roller2008. Although the example cells 2020 are shown as being a quadrilateralin FIG. 20A, the cells 2020 can take on any shape in other examples.Each cell may have a respective size (e.g., respective widths andrespective depths). The size of each cell may depend on at least thefollowing factors: the size of the elements included in the fluid 2004;the parts of the printing plate 2014 that are used to accept the fluid2004 from the second cylindrical structure 2008 and imprint the uniquemarker into the substrate 2018; the size of the unique marker(s) thatare imprinted into the substrate 2018; and the amount of fluid 2004needed to imprint the substrate 2018. In some cases, the etched cells2020 may be designed to carry a specific transfer volume of fluid 2004to the printing plate 2014. In some instances, there may be amathematical relationship between the size of the elements included inthe fluid 2004 and the minimum cell or pattern width on the secondcylindrical structure 2008. For example, in some implementations of theflexography printing system 2000, each of the cells 2020 have a width Wup to 300 microns at their widest dimension (e.g., in a range from about20 microns to about 300 microns). In another example, in someimplementations of the flexography printing system 2000, the systems andmaterials can be engineered such that a cell's volume is at least anorder of magnitude larger than the average width (e.g., diameter) of theelements (e.g., a fluid 2004 containing diamond particles having anaverage width of 10-microns can be used with cells of 100 micron³,etc.).

In some instances, the sizes of the cells and other features of theflexography printing system 2000 can be engineered to create uniquemarkers with specified properties (e.g., size, shape, spatial density ofelements, spatial distribution of elements, etc.). Furthermore, taggedand untagged patterns on the substrate 2018 can be designed by modifyingthe geometry of the etched cells 2020 to carry more or less taggingmaterial (e.g., the fluid 2004). FIG. 20B shows a zoomed-in top-downview of some cells 2022 that are designed to have different dimensionsso that unique markers with a specified shape (e.g., an X-shape) can becreated. For example, each cell of a first group of cells 2024 hasdimensions (e.g., widths, depths, or both) that are greater than eachcell of a second group of cells 2026. Consequently, the fluid 2004 iscapable of filling cells from the first group of cells 2024, but notcells from the second group of cells 2026 (e.g., due to their smallerdimension). In some implementations, the volume of each cell from thefirst group of cells 2024 is at least an order of magnitude larger thanthe average width (e.g., diameter) of the elements (e.g., a fluid 2004containing diamond particles having an average width of 10-microns canbe used with cells of 100 micron³, etc.).

FIG. 21 is a schematic diagram of an example rotogravure system 2100.The example rotogravure system 2100 can be used to form a unique markerthat is shaped to the surface morphology of an object. The rotogravuresystem 2100 includes a fountain 2102. In some implementations, thefountain 2102 is a container that contains a fluid (e.g., a liquid orviscous fluid) 2104 containing a distribution of elements (e.g.,crystalline particles or other types of elements) that is used to formthe unique marker. The fluid 2104 may be similar to the fluid 1904described above in relation to FIGS. 19C, 19D, 19E.

The rotogravure system 2100 includes a first cylindrical structure 2106(e.g., a gravure cylinder) that is at least partially submerged in thefluid 2104. In some implementations, the first cylindrical structure2106 may be a metal (e.g., steel or copper) cylinder, although othermaterials (e.g., ceramics) can also be used. During operation of therotogravure system 2100, the first cylindrical structure 2206 rotates(e.g., in a clockwise direction in the example of FIG. 21) so that, asthe first cylindrical structure 2106 rotates, the fluid 2104 coats theportion of the first cylindrical structure 2106 that is not submerged inthe fluid 2104.

In some implementations, the outer surface of the first cylindricalstructure 2106 includes patterned or etched cells, channels, or otherdepressed features that that function as carriers for the fluid 2104.During operation of the rotogravure system 2100, the first cylindricalstructure 2106 rotates, and the fluid 2004 from the first cylindricalstructure 2006 fills the etched cells that are formed on the surface ofthe first cylindrical structure 2106. In some implementations, therotogravure system 2100 includes an optional removal instrument 2108(e.g., a doctor blade) that removes excess material of the fluid 2104from the etches cells that are formed on the surface of the firstcylindrical structure 2106.

The rotogravure system 2100 includes a second cylindrical structure 2110(e.g., an impression roll). In some implementations, the secondcylindrical structure 2110 may be a metal (e.g., steel or copper)cylinder, although other materials (e.g., ceramics) also be used.

During operation of the rotogravure system 2100, a substrate 2112 (e.g.,metal, plastic, wood, leather, etc.) is placed between the secondcylindrical structure 2110 and the first cylindrical structure 2106. Thesecond cylindrical structure 2110 applies pressure to the firstcylindrical structure 2106 and the rotates (e.g., in a counter-clockwisedirection in the example of FIG. 21), thereby imprinting the substrate2112 with an indentation and transferring the fluid 2104 to thesubstrate 2112 such that the fluid 2104 conforms with the morphology ofthe indentation. In some instances, the substrate 2112 having the fluid2104 may be cured (e.g., by ordinary drying, exposure to an energysource such as UV radiation, or another process) to set the spatialdistribution and relative orientations of the elements in the fluid 2104and form the unique marker. In some implementations, the rotogravuresystem 2100 can be used to create numerous, patterned unique markers inor on the substrate 2112 alongside untagged areas that are printednormally. The substrate 2112 having the unique marker can subsequentlybe used to manufacture the product or article.

Similar to the flexography printing system 2000, in the rotogravuresystem 2100, the size of each cell may depend on at least the followingfactors: the size of the elements included in the fluid 2104; the partsof the first cylindrical structure 2106 that are used to imprint theunique marker into the substrate 2112; the size of the unique marker(s)that are imprinted into the substrate 2112; and the amount of fluid 2104needed to imprint the substrate 2112. Similar to the flexographyprinting system 2000, in the rotogravure system 2100, there may be amathematical relationship between the size of the elements included inthe fluid 2104 and the minimum cell or pattern width on the firstcylindrical structure 2106.

In the examples discussed in FIGS. 18A, 18B, 19A, 19B, 19C, 19D, 19E,20A, 20B, and 21, manufacturers can tailor specific features andlocations on a substrate to contain a unique marker containing adistribution of elements (e.g., crystalline particles or other types ofelements), thus providing a secure fingerprint for the underlyingsubstrate. The unique marker can conform to the substrate's indentation,allowing indented logos or other surface features to serve as a covert,secure identifier for a brand, or to hide a tag from exposure tophysical environmental factors. In some cases, such as in the examplesof FIGS. 20A, 20B, and 21, unique markers can be replicated withinetched cells on printing rollers and be used to impart shaped tags ontoa substrate or printing plate to mass-produce tags of a specific shape.In some cases where a product may have indentations that are random(e.g., as found on the surfaces of natural materials like wood andleather), the unique marker may integrate into the creases, cracks, andetchings (e.g., common to many luxury goods). In some implementations,the unique markers that are produced may range in size, for example,from microscopic (e.g., having a surface area in the 1 μm² to 1000 μm²range) to macroscopic (e.g., having a surface area in the 1 mm² to 1000mm² range).

In some implementations, a physically unclonable unique marker iscombined with an adhesive/sealant material to establish a uniqueidentity on an underlying object or interface. FIGS. 22A and 22B showexamples where a distribution of elements is imbedded on a front surfaceof a substrate with an adhesive backing. In the examples of FIGS. 22Aand 22B, the unique marker may be similar to a sticker or a label (e.g.,a pre-made “peel-and-stick” tag). FIG. 22A shows the example of a singletag 2200 prior to its application on an underlying object or interface.FIG. 22B shows an example where multiple single tags 2200 (e.g., fromFIG. 22A) are arranged in the form of a tape or roll 2208.

The tag 2200 can be a sticker. In some instances, a sticker includes asubstrate 2202 having a distribution of elements 2204 (e.g., crystallineparticles or other types of elements) formed on a front surface of thesubstrate 2202. The substrate 2202 may, as an example, be paper,plastic, or any suitable flexible substrate for a sticker or label(e.g., multi-part sticker or multi-part label). The substrate 2202 mayhave a first portion 2202A and a second portion 2202B, both of which mayhave elements 2204 distributed therein. In the example of FIG. 22A, thefirst portion 2202A and the second portion 2202B are demarcated by aperforation 2203 or a similar boundary. At least a portion of thesubstrate 2202 may have an adhesive backing (e.g., an adhesive formed ona back surface of the substrate 2202). For example, the first portion2202A of the substrate 2202 may have an adhesive backing, while thesecond portion 2202B of the substrate 2202 may be devoid of an adhesivebacking. In another example, both the first and second portions 2202A,2202B of the substrate 2202 may have an adhesive backing. In someimplementations, the adhesive can be one or more of the followingmaterials: epoxies; urethanes; hot-melts; silicones; polyimides;latexes; acrylics; clear-coats; paints; marine greases; ordinarypressure-sensitive adhesives; non-reactive adhesives; thermosettingadhesives; chemically-reactive adhesives; or physically-reactiveadhesives.

In some instances, the tag 2200 may be analyzed prior to its applicationto an underlying object or interface. As an illustration, properties ofthe tag 2200 may be obtained by generating a unique code, for example,according to the example processes 1400, 1500 shown in FIGS. 14 and 15,or another type of process. In some instances, properties may beobtained by generating orientation information, for example, theorientation information 1206, 1306 shown in FIGS. 12 and 13, or anothertype of orientation information.

When the tag 2200 is applied to the underlying object or interface, thefirst portion 2202A (e.g., having the adhesive backing) is separatedfrom the second portion 2202B, and the first portion 2202A forms theunique marker 2206. The unique marker 2206 can then be applied to theunderlying object or interface. In some implementations, the uniquemarker 2206 can be analyzed after its application to the product orinterface. Additionally or alternatively, properties of the secondportion 2202B of the substrate 2202 (e.g., the remaining portion of thetag 2200) can be obtained after the unique marker 2206 is applied to theproduct or interface. As an illustration, properties of the remainingportion of the tag 2200 and the unique marker 2206 may be obtained bygenerating a unique code, for example, according to the exampleprocesses 1400, 1500 shown in FIGS. 14 and 15, or another type ofprocess. In some instances, properties may be obtained by generatingorientation information, for example, the orientation information 1206,1306 shown in FIGS. 12 and 13, or another type of orientationinformation. The properties of the tag 2200 (obtained prior to itsapplication to the underlying object or interface), the unique marker2206, and the remaining portion of the tag 2200 can be compared toanalyze the underlying object or interface (e.g., to authenticateidentity, provide evidence of tampering, provide evidence of use,provide evidence of exposure to environmental stress, provide evidenceof exposure to mechanical stress or wear, etc.).

Consequently, in the example of FIGS. 22A and 22B, a multi-part tag orsticker 2200 (e.g., label 2202A and backing 2202B) is shown, where thetag 2200 is scannable/enrollable when the label 2202A and backing 2202Bare together and only part(s) of the tag 2200 (e.g., the label 2202A)are transferred via the sticker/adhesive onto the object such that theidentification can be made before and after application onto theunderlying object or interface. The remaining portion 2202B of the tag2200 (e.g., the backing/non-adhesive part) can also be identified andtied to the application event on the underlying object or interface. Asan example, initial orientation information can be extracted from thesticker 2200 before the first portion 2202A of the sticker 2200 isapplied to the object. An initial orientation information can beindicative of the relative spatial orientations of the respectiveelements 2204 across the entire sticker 2200, and an initial unique code(that is associated with the entire sticker 2200) can be generated basedon the initial orientation information. The first portion 2202A cansubsequently be separated from the second portion 2202B and placed onthe object. Orientation information from the first portion 2202A of thesticker 2200 (which is on the object) can be extracted, and theorientation information can indicate the relative spatial orientationsof the respective elements 2204 of the first portion 2202A of thesticker 2200. A unique code for the object can subsequently be generatedbased on the orientation information of the first portion 2202A of thesticker 2200. In some implementations, after the first portion 2202A ofthe sticker 2200 has been placed on the object, second orientationinformation can be extracted from the second portion 2202B of thesticker 2200. The second orientation information can be indicative ofthe relative spatial orientations of the respective elements 2204 of thesecond portion 2202B of the sticker 2200. A second unique code cansubsequently be generated based on the orientation information of thesecond portion 2202B of the sticker 2200. The second unique code can beassociated with the application of the first portion 2202B of thesticker 2200 on the object.

In the examples of FIGS. 22A and 22B, the distribution of elements(e.g., crystalline particles or other types of elements) is formed on asurface of a substrate, and the adhesive is formed on a back surface ofthe substrate. However, in other examples, the elements may bedistributed within the adhesive itself. FIG. 23 shows an example where adistribution of elements 2300 is placed within an adhesive 2302 that isnot fully cured. In the example of FIG. 23, the adhesive 2302 is uncuredor semi-cured and may have a gel-like consistency. In someimplementations, the adhesive 2302 can be one or more of the followingmaterials: epoxies; urethanes; hot-melts; silicones; polyimides;latexes; acrylics; clear-coats; paints; marine greases; ordinarypressure-sensitive adhesives; non-reactive adhesives; thermosettingadhesives; chemically-reactive adhesives; or physically-reactiveadhesives.

The adhesive 2302 containing the distribution of elements 2300 issandwiched between liners 2304, 2306. The liners 2304, 2306 may, as anexample, be UV-blocking lining papers. The adhesive 2302 can be used toform a unique marker that is applied to an underlying object orinterface. For example, the liners 2304, 2306 can be removed, thusexposing the adhesive 2302. The adhesive 2302 can then be applied to anunderlying object or interface. The underlying object or interface(having the adhesive 2302) can then go through a hardening process(e.g., ordinary drying, curing, by exposure to an energy source (e.g. UVradiation), or another process) that causes the adhesive 2302 tosolidify, thus allowing the adhesive 2302 (containing the distributionof elements 2300) to gain a physically unclonable identity whilemaintaining its functional purpose (e.g., decorative, informative,protective, etc.) within the design of the underlying object orinterface. The properties of the hardened adhesive 2302 may be obtainedby generating a unique code, for example, according to the exampleprocesses 1400, 1500 shown in FIGS. 14 and 15, or another type ofprocess. In some instances, properties may be obtained by generatingorientation information, for example, the orientation information 1206,1306 shown in FIGS. 12 and 13, or another type of orientationinformation. The properties of the hardened adhesive 2302 can be used toanalyze the underlying object or interface (e.g., to authenticateidentity, provide evidence of tampering, provide evidence of use,provide evidence of exposure to environmental stress, provide evidenceof exposure to mechanical stress or wear, etc.).

In the examples of FIGS. 22A, 22B, and 23, the unique markers may bepre-formed into specific shapes or die-cut from a larger tag or taggedsheet (which itself could be produced using extrusion processes).Furthermore, the unique markers may have elastic properties that showevidence of tampering via deformation if removal is attempted, whilemaintaining the unique markers' ability to be identified successfully.The unique markers may also be mass produced via manufacturing processesthat shape the unique markers to a surface morphology of a product(e.g., as discussed above in FIGS. FIGS. 18A, 18B, 19A, 19B, 19C, 19D,19E, 20A, 20B, and 21).

In some implementations, the distribution of elements (e.g., crystallineparticles or other types of elements) can be combined with a sealantmaterial (e.g., coating, potting compound, paint, etc.). Thedistribution of elements can be pre-mixed within an uncured sealantmaterial or added to the surface of an applied, but uncured, sealantmaterial, and an identity is created during or after the curing process.The sealant material can be applied to an underlying object or interfacethrough a variety of methods such as spraying, dipping, painting, orextruding.

FIG. 24 shows an example where both a distribution of elements 2400 anda sealant material 2402 are incorporated into a handheld applicator 2404having a nozzle or tip 2406. The texture of the surface 2408 on whichthe handheld applicator 2404 is placed is used to remove material out ofthe handheld applicator 2404 and mark or coat specific areas of thesurface 2404 with uncured material, which is subsequently cured to formthe unique marker 2410. The example shown in FIG. 24 may be analogous tomarine grease incorporated into a pen form-factor with a polymeradhesive, or a paint marker.

In some cases, the sealant can be used, for example, to fill small voidsof any form (e.g., interfaces, holes, cracks, crazing, gaps betweensurfaces, etc.). FIGS. 25A and 25B show examples where a distribution ofelements (e.g., crystalline particles or other types of elements) may beincorporated into a sealant to seal interfaces and electronicenclosures. In the example shown in FIG. 25A, a sealant 2500 containinga distribution of elements 2502 is applied by a sealant applicator 2504to fill an interface or gap 2506 in an underlying object 2507. Thesealant 2500 can be uncured or semi-cured as it fills the interface orgap 2506. The sealant 2500 may be subsequently cured to form a uniquemarker 2508 that secures the interface or gap 2506. The properties ofthe unique marker 2508 may be obtained by generating a unique code, forexample, according to the example processes 1400, 1500 shown in FIGS. 14and 15, or another type of process. In some instances, properties may beobtained by generating orientation information, for example, theorientation information 1206, 1306 shown in FIGS. 12 and 13, or anothertype of orientation information. The properties of the unique marker2508 can be used to analyze the underlying object or interface (e.g., toauthenticate identity, provide evidence of tampering, provide evidenceof use, provide evidence of exposure to environmental stress, provideevidence of exposure to mechanical stress or wear, etc.).

In the example shown in FIG. 25B, a sealant 2510 (e.g., a pottingcompound or resin) containing a distribution of elements 2512 is used toseal an electronic enclosure 2514 containing one or more electroniccomponents 2516. The sealant 2510 can be uncured or semi-cured as itfills the electronic enclosure 2514. The sealant 2510 may besubsequently cured to set the spatial distribution and relativeorientations of the elements in the sealant 2510. The properties of thesealant 2510 may be obtained by generating a unique code, for example,according to the example processes 1400, 1500 shown in FIGS. 14 and 15,or another type of process. In some instances, properties may beobtained by generating orientation information, for example, theorientation information 1206, 1306 shown in FIGS. 12 and 13, or anothertype of orientation information. The properties of the sealant 2510 canbe used to analyze the electronic enclosure 2514 (e.g., to authenticateidentity, provide evidence of tampering, provide evidence of use,provide evidence of exposure to environmental stress, provide evidenceof exposure to mechanical stress or wear, etc.). Analysis of theelectronic enclosure 2514 may reveal whether one or more of theelectronic components 2516 needs to be serviced or repaired.

In the example of FIG. 25B, the elements 2512 are evenly distributed inthe sealant 2510. However, in other examples, such as in the examplesshown in FIGS. 26A, and 26B, the elements 2512 may be distributed inonly a portion of the sealant 2510. Specifically, in FIG. 26A, thedistribution of elements is formed as a conformal coating 2612A on theelectronic components 2516, and the sealant 2610A (which issubstantially clear and free from elements) is formed over the conformalcoating 2612A. In FIG. 26B, the sealant 2610B (which is substantiallyclear and free from elements) is formed on the electronic components2516, and the distribution of elements is formed as a conformal coating2612B on sealant 2610B.

FIGS. 27A and 27B show example processes for forming a conformal coatingon an underlying substrate or object. In the example of FIG. 27A, aspray gun 2700 can be used to form a conformal coating of elements 2702on an object 2704. In some instances, a sealant containing thedistribution of elements can be placed in a cup 2706. The sealantcontaining the distribution of elements is subsequently sprayed onto theobject 2704. In some instances, the spray gun 2700 may be agitated whilespraying to ensure dispersion of the distribution of elements over oneor more surfaces of the object 2704. In the example of FIG. 27B, ananalogous process may be used to form a conformal coating of elements onone or more electronic components 2708. For example, a sealant 2710(e.g., a potting compound or resin) containing a distribution ofelements can be sprayed (using a spraying equipment 2712) onto one ormore electronic components 2708 to form a conformal coating of elements(e.g., as shown in the example of FIG. 26A).

In some instances, a sealant containing a distribution of elements couldserve as a gasket that can provide evidence of deformation due tochanges in pressure. FIG. 28 shows an example where an enclosure 2800 isprovided with a gasket 2802 having a distribution of elements 2804. Insome implementations, the gasket 2802 is formed from a sealant materialincluding the distribution of elements 2804. The gasket 2802 may bedeformed due to changes in pressure. In some implementations, theproperties of the gasket 2802 can be analyzed to determine whether theenclosure 2800 has been exposed to changes in pressure. The propertiesof the gasket 2802 may be obtained by generating a unique code, forexample, according to the example processes 1400, 1500 shown in FIGS. 14and 15, or another type of process. In some instances, properties may beobtained by generating orientation information, for example, theorientation information 1206, 1306 shown in FIGS. 12 and 13, or anothertype of orientation information. The properties of the gasket 2802 canbe used to analyze the enclosure 2800 (e.g., to authenticate identity,provide evidence of tampering, provide evidence of use, provide evidenceof exposure to environmental stress, provide evidence of exposure tomechanical stress or wear or changes in pressure, etc.).

In the examples shown in FIGS. 22A, 22B, 23, 24, 25A, 25B, 26A, 26B,27A, 27B, and 28, a single sealing or coating step can be used to createmultiple identification areas on a substrate (e.g. the coating may beused to provide multiple points of identification for added security orthe ability to tag multiple sub-components by coating them in a singleprocess). Furthermore, these examples create a continuous scanning area(as opposed to a single scanning point), whereby the scanner validatesthe distribution of elements as it moves across the surface, and maydetect changes in the surface coating as a function of location, thusallowing for analysis of the underlying object or interface (e.g., toauthenticate identity, provide evidence of tampering, provide evidenceof use, provide evidence of exposure to environmental stress, provideevidence of exposure to mechanical stress or wear or changes inpressure, etc.).

The examples shown in FIGS. 22A, 22B, 23, 24, 25A, 25B, 26A, 26B, 27A,27B, and 28 also have at least the following features. Stickers orlabels can use a distribution of elements to provide an unclonableidentity for security and tracking applications. In some instances, thedistribution of elements is incorporated into an uncuredadhesive/sealant material and cured upon application, therebyestablishing an identity. The stickers or labels can combine a covertanalysis function with at least one of a decorative function or aprotective function (for example, when used within coatings onvehicles). The stickers or labels can form a unique marker that providesboth identity and evidence of tampering/environmental stress asevidenced though deformations to the unique marker. The stickers orlabels can create both scannable points and scannable regions that carryidentities and other information. The stickers or labels provide a wayof incorporating a secure, unclonable identity covertly or overtly intostickers, labels, sealants, coatings, adhesives and paint (which may beapplied in some cases through convenient and conventional processes) andmaintaining the medium's existing functionality (decorative,informative, protective, etc.), which may allow products to have innatesecurity, traceability, and binding to digital records.

When protecting physical goods, one key layer of security is ensuringthat owners can tell whether unauthorized third parties have attemptedto access an article. A unique marker including a distribution ofelements (e.g., crystalline particles or other types of elements) can beincorporated as a security layer into the packaging and/or into theproduct itself, via an enclosure, fastener, joint, component or otherattack point. For example, the unique marker can be applied to products,components, parts, enclosures, fasteners, or other articles whereidentity, traceability, and security/tamper evidence is desired. Inaddition to demonstrating evidence of tampering with the tagged object(e.g., product and/or packaging), the unique marker can be used toauthenticate identity of the tagged object. In some instances, partialdeformation, alteration, modification or destruction of the uniquemarker does not prevent a unique marker's unique code from beingrecognized or reasonably calculated. However, the unique marker may notbe reusable and may be deformed because of the tampering.

Consequently, tampering may cause a change in the unique marker's uniquecode. In some instances, tampering (e.g., removal and replacement of aunique marker) may trigger a tamper alert upon authentication of theobject.

FIG. 29 shows an example of a tagged area 2900 that can be used toauthenticate identity and to provide evidence of tampering. In someinstances, the tagged area 2900 has a unique marker that includes adistribution of elements 2902 (e.g., crystalline particles or othertypes of elements). The unique marker can include a first region 2904, asecond region 2906, and a third region 2908. The second region 2906 andthe third region 2908 may, as an example, collectively form a taggedscrew head, and the first region 2904 may be a region of a substratesurrounding the tagged screw head. In some instances, the first region2904 and the second region 2906 may be used to authenticate the identityof the object and may also be used to provide evidence of whether thescrew was turned. In some examples, the third region 2908 can showevidence of destruction of the unique marker (e.g., if force is appliedto the third region 2908).

In some implementations, depending on the underlying surface morphology,a system (e.g., the system shown in FIG. 4) may determine areas withinthe unique marker that will show evidence of tamper, and areas that willnot, which can then be used to verify the unique marker's identity. Forexample, the system may determine the center of the unique marker andanalyze the changes in the unique marker in a radial manner, or it maysegregate the unique marker into multiple sectors (as in the exampleshown in FIG. 29) and analyze changes within and between sectors.

In the example shown in FIG. 29, for example, the system may usesimilarities of local pixels within an image of the tagged area 2900 toderive local morphologic similarity, and may use a variety of grainingor smoothing operations to include or exclude those features. Onsubsequent scans of the tagged area 2900, the system may identify theunique marker and then performs a differential analysis of the uniquemarker against reference images to elicit evidence of tampering.

In some cases, unique markers may be utilized on a pre-designated tamperpoint. A tamper point can be any area of an object (e.g., product or theproduct's packaging) that can be opened or breached, thus allowing athird party to alter a shape of the object or to access the contents ofthe object. Stated differently, tampering can cause the unique marker toundergo deformation when a third party tries to open, replace, ormaterially change the product or product's packaging. FIGS. 30, 31, 32,33, 34, and 35 show examples where unique markers are utilized on tamperpoints to provide evidence of tampering.

FIG. 30 is a diagram of a box 3000 that includes a unique marker 3002 onan edge of the box 3000. In the example of FIG. 30, the box 3000 is usedas packaging for an object. The unique marker 3002 including adistribution of elements (e.g., crystalline particles or other types ofelements) is placed across a seam of or entry-point into the box 3000.In the example of FIG. 30, the unique marker 3002 is in the form of atape. When the box 3000 is opened, the unique marker 3002 is altered(e.g., torn). An attempt to reseal the box 3000 causes tears andmisalignment 3004 in the unique marker 3002. Tampering can beinvestigated by analyzing the properties of the unique marker 3002. Theproperties of the unique marker 3002 may be obtained by generating aunique code, for example, according to the example processes 1400, 1500shown in FIGS. 14 and 15, or another type of process. In some instances,properties may be obtained by generating orientation information, forexample, the orientation information 1206, 1306 shown in FIGS. 12 and13, or another type of orientation information, thus providing evidenceof tampering with the box 3000.

FIG. 31 is a diagram of a box 3100 that includes a unique marker 3102 ona seam of the box 3100. In the example of FIG. 31, the box 3100 is usedas packaging for an object. The unique marker 3102 including adistribution of elements (e.g., crystalline particles or other types ofelements) is placed across a seam of or entry-point into the box 3100.In the example of FIG. 31, the unique marker 3102 is in the form of anadhesive that is placed across the seam or entry-point of the box 3100.When the box 3100 is opened, the unique marker 3102 is altered (e.g.,torn). An attempt to reseal the box 3100 causes tears and misalignment3104 in the unique marker 3102. Tampering can be investigated byanalyzing the properties of the unique marker 3102. The properties ofthe unique marker 3102 may be obtained by generating a unique code, forexample, according to the example processes 1400, 1500 shown in FIGS. 14and 15, or another type of process. In some instances, properties may beobtained by generating orientation information, for example, theorientation information 1206, 1306 shown in FIGS. 12 and 13, or anothertype of orientation information, thus providing evidence of tamperingwith the box 3100.

FIG. 32 is a diagram of a film 3200 that includes a unique marker 3204.In the example of FIG. 32, a film 3200 (e.g., a plastic wrap) is placedover an object 3202 (e.g., a die) to produce a shrink-wrapped product. Aunique marker 3204 including a distribution of elements 3205 (e.g.,crystalline particles or other types of elements) is placed on the film3200. Tampering with the film 3200 may relieve tension in the substrate(e.g., the film 3200), thus causing deformation of the unique marker3204. Tampering can be investigated by analyzing the properties of theunique marker 3204. The properties of the unique marker 3204 may beobtained by generating a unique code, for example, according to theexample processes 1400, 1500 shown in FIGS. 14 and 15, or another typeof process. In some instances, properties may be obtained by generatingorientation information, for example, the orientation information 1206,1306 shown in FIGS. 12 and 13, or another type of orientationinformation, thus providing evidence of tampering with the film 3200.

FIG. 33 is a diagram of a fastener 3300 having a unique marker 3302placed on a clutch of the fastener 3300. In the example of FIG. 33, thefastener 3300 (e.g., a zip-tie) may be used to fasten a product to apackaging. The unique marker 3302 including a distribution of elements(e.g., crystalline particles or other types of elements) may be placedon the clutch 3304 of the fastener 3300. Tampering with the fastener3300 can cause deformation to the unique marker 3302. Tampering can beinvestigated by analyzing the properties of the unique marker 3302. Theproperties of the unique marker 3302 may be obtained by generating aunique code, for example, according to the example processes 1400, 1500shown in FIGS. 14 and 15, or another type of process. In some instances,properties may be obtained by generating orientation information, forexample, the orientation information 1206, 1306 shown in FIGS. 12 and13, or another type of orientation information, thus providing evidenceof tampering with the fastener 3300.

FIG. 34 is a diagram of an article's enclosure 3400 having a uniquemarker 3402 placed on a seam of the enclosure 3400. In the example ofFIG. 34, the unique marker 3402 includes a distribution of elements(e.g., crystalline particles or other types of elements). The uniquemarker 3402 can be placed across a seam 3404 of the enclosure 3400. Theunique marker 3402 can also be placed across any impermanent joint orinterface between surfaces. When the enclosure 3400 is opened, theunique marker 3402 is altered (e.g., torn). An attempt to reseal theenclosure 3400 causes tears and misalignment 3406 in the unique marker3402. Tampering can be investigated by analyzing the properties of theunique marker 3402. The properties of the unique marker 3402 may beobtained by generating a unique code, for example, according to theexample processes 1400, 1500 shown in FIGS. 14 and 15, or another typeof process. In some instances, properties may be obtained by generatingorientation information, for example, the orientation information 1206,1306 shown in FIGS. 12 and 13, or another type of orientationinformation, thus providing evidence of tampering with the enclosure3400.

FIG. 35 is a diagram of a microchip 3500 provided with unique markers3502 at solder points 3504. Each of the unique markers 3502 includes adistribution of elements (e.g., crystalline particles or other types ofelements). In an event of tampering with the microchip 3500, a nefariousthird party may attempt to provide signals to (or receive signals from)the microchip 3500 via one or more of the solder points 3504, thusdamaging the respective unique markers 3502. Tampering can beinvestigated by analyzing the properties of the unique markers 3502. Theproperties of the unique markers 3502 may be obtained by generating aunique code, for example, according to the example processes 1400, 1500shown in FIGS. 14 and 15, or another type of process. In some instances,properties may be obtained by generating orientation information, forexample, the orientation information 1206, 1306 shown in FIGS. 12 and13, or another type of orientation information, thus providing evidenceof tampering with the microchip 3500.

FIG. 36 shows an example where a unique marker 3600 can be used toprovide evidence of use or activation of an object. In the example ofFIG. 36, the object includes heat sink blades 3602 that heat up when theobject is activated or in use. In some instances, the heat sink blades3602 can also heat up when the object is exposed to environmental stress(e.g., high temperatures). The unique marker 3600, which includes adistribution of elements (e.g., crystalline particles or other types ofelements), is placed on one or more of the heat sink blades 3602. Whenthe object is in use or activated, the heat sink blades 3602 heat up,thus causing deformation (e.g., melting) of the unique marker 3600. Useor activation of the object can be investigated by analyzing theproperties of the unique marker 3600. The properties of the uniquemarker 3600 may be obtained by generating a unique code, for example,according to the example processes 1400, 1500 shown in FIGS. 14 and 15,or another type of process. In some instances, properties may beobtained by generating orientation information, for example, theorientation information 1206, 1306 shown in FIGS. 12 and 13, or anothertype of orientation information, thus providing evidence of use oractivation of the object.

FIG. 37 shows an example where a unique marker 3700 can be used toprovide evidence of an external force applied to a tagged surface. Inthe example of FIG. 37, a surface of an object 3702 is provided with theunique marker 3700 including a distribution of elements (e.g.,crystalline particles or other types of elements). When an externalforce 3704 is applied to the surface by another object 3706, a portion3708 of the unique marker 3700 may become dislodged from the surface ofthe object 3702. Application of an external force to the surface of theobject 3702 can be investigated by analyzing the properties of theunique marker 3700. The properties of the unique marker 3700 may beobtained by generating a unique code, for example, according to theexample processes 1400, 1500 shown in FIGS. 14 and 15, or another typeof process. In some instances, properties may be obtained by generatingorientation information, for example, the orientation information 1206,1306 shown in FIGS. 12 and 13, or another type of orientationinformation, thus providing evidence of an external force applied to atagged surface.

In the examples of FIGS. 29 to 37, the tampering of one unique markercan trigger an inspection or quarantine of all other associated uniquemarkers (e.g. the box displays tamper evidence, so the enclosed productand its tags can be flagged for further review). Furthermore, in theexamples of FIGS. 29 to 37, a system may segregate the regions withinthe unique marker based on their susceptibility to showing tamper (e.g.,as in the example of FIG. 29). Depending on the security needs of thetagged object, an operator may define different levels of sensitivity toalteration of changes in the unique marker that may trigger alerts.Additionally or alternatively, the system may automatically define itsown detection sensitivity to alterations. The system may render theresult of the differential analysis: if the unique marker is damagedbeyond identification, the unique marker may be designated astamper-evident and submit to a security audit; if the unique markerexceeds any of multiple possible defined levels of alteration, then thesystem may authenticate the unique marker's identity, and alert theoperator of the results of the analysis, and provide a set of actions toresolve; if the unique marker shows a minimal level alteration,depending on the security level and the nature of the tagged substrate(e.g. screw head), then the system may authenticate the tag's identityand provide validation that no tampering likely occurred.

FIG. 38 is a flow diagram schematically illustrating an example process3800 for forming and using a unique marker that conforms with a surfacemorphology of an object. At 3802, an object having a surface feature isreceived. The surface feature can be a facet of the object, a surface ofone or more components of the object, or surface patterns, textures, orother indentations of the object. Furthermore, the object can be anysolid material (metal, plastic, wood, leather, etc.), and the surfacefeature may be made, for example, via stamping, engraving, etching, orotherwise patterning the object. At 3804, a unique marker is formed onthe surface feature of the object. Any of the processed discussed abovein the examples shown in FIGS. 19A, 19B, 19C, 19D, 19E, 20A, 20B, 21,22A, 22B, 23, 24, 25A, 25B, 26A, 26B, 27A, 27B, and 29 to 37 may be usedto form the unique marker on the surface feature of the object. Theunique marker includes a distribution of elements (e.g., crystallineparticles or other types of elements) and conforms with a morphology orshape of the surface feature. At 3806, orientation information isextracted from the unique marker. The orientation information can be,for example, the orientation information 1206, 1306 shown in FIGS. 12and 13, or another type of orientation information. At 3808, a uniquecode is generated for the object based on the orientation information,for example, according to the example processes 1400, 1500 shown inFIGS. 14 and 15, or another type of process. The unique code cansubsequently be used to analyze the object (e.g., to authenticate theidentity of the object, determine whether the object has been tamperedwith, determine whether the object has been used or activated, determinewhether the object has been exposed to environmental stress, determinewhether the object has been subjected to mechanical stress or wear, orother types of analysis of the object).

FIG. 39 is a flow diagram schematically illustrating an example process3900 for forming and using a sticker including a distribution ofelements on a substrate having an adhesive backing. At 3902, a stickerincluding a distribution of elements on a substrate having an adhesivebacking is provided. As an example, the sticker 2200 shown in FIG. 22Amay be provided. At 3904, at least a portion of the sticker (e.g., thefirst portion 2202A of the sticker 2200) is applied to the object. At3906, orientation information is extracted from the portion of thesticker that is on the object. The orientation information can be, forexample, the orientation information 1206, 1306 shown in FIGS. 12 and13, or another type of orientation information. At 3908, a unique codeis generated for the object based on the orientation information, forexample, according to the example processes 1400, 1500 shown in FIGS. 14and 15, or another type of process. The unique code can subsequently beused to analyze the object (e.g., to authenticate the identity of theobject, determine whether the object has been tampered with, determinewhether the object has been used or activated, determine whether theobject has been exposed to environmental stress, determine whether theobject has been subjected to mechanical stress or wear, or other typesof analysis of the object).

Some of the subject matter and operations described in thisspecification can be implemented in digital electronic circuitry, or incomputer software, firmware, or hardware, including the structuresdisclosed in this specification and their structural equivalents, or incombinations of one or more of them. Some of the subject matterdescribed in this specification can be implemented as one or morecomputer programs, i.e., one or more modules of computer programinstructions, encoded on a computer storage medium for execution by, orto control the operation of, data-processing apparatus. A computerstorage medium can be, or can be included in, a computer-readablestorage device, a computer-readable storage substrate, a random orserial access memory array or device, or a combination of one or more ofthem. Moreover, while a computer storage medium is not a propagatedsignal, a computer storage medium can be a source or destination ofcomputer program instructions encoded in an artificially generatedpropagated signal. The computer storage medium can also be, or beincluded in, one or more separate physical components or media (e.g.,multiple CDs, disks, or other storage devices).

Some of the operations described in this specification can beimplemented as operations performed by a data processing apparatus ondata stored on one or more computer-readable storage devices or receivedfrom other sources.

The term “data-processing apparatus” encompasses all kinds of apparatus,devices, and machines for processing data, including by way of example aprogrammable processor, a computer, a system on a chip, or multipleones, or combinations, of the foregoing. The apparatus can includespecial purpose logic circuitry, e.g., an FPGA (field programmable gatearray) or an ASIC (application specific integrated circuit). Theapparatus can also include, in addition to hardware, code that createsan execution environment for the computer program in question, e.g.,code that constitutes processor firmware, a protocol stack, a databasemanagement system, an operating system, a cross-platform runtimeenvironment, a virtual machine, or a combination of one or more of them.

A computer program (also known as a program, software, softwareapplication, script, or code) can be written in any form of programminglanguage, including compiled or interpreted languages, declarative orprocedural languages, and it can be deployed in any form, including as astand-alone program or as a module, component, subroutine, object, orother unit suitable for use in a computing environment. A computerprogram may, but need not, correspond to a file in a file system. Aprogram can be stored in a portion of a file that holds other programsor data (e.g., one or more scripts stored in a markup languagedocument), in a single file dedicated to the program, or in multiplecoordinated files (e.g., files that store one or more modules, subprograms, or portions of code). A computer program can be deployed to beexecuted on one computer or on multiple computers that are located atone site or distributed across multiple sites and interconnected by acommunication network.

Some of the processes and logic flows described in this specificationcan be performed by one or more programmable processors executing one ormore computer programs to perform actions by operating on input data andgenerating output. The processes and logic flows can also be performedby, and apparatus can also be implemented as, special purpose logiccircuitry, e.g., an FPGA (field programmable gate array) or an ASIC(application specific integrated circuit).

Processors suitable for the execution of a computer program include, byway of example, both general and special purpose microprocessors, andprocessors of any kind of digital computer. Generally, a processor willreceive instructions and data from a read-only memory or a random-accessmemory or both. Elements of a computer can include a processor thatperforms actions in accordance with instructions, and one or more memorydevices that store the instructions and data. A computer may alsoinclude, or be operatively coupled to receive data from or transfer datato, or both, one or more mass storage devices for storing data, e.g.,magnetic disks, magneto optical disks, or optical disks. However, acomputer need not have such devices. Moreover, a computer can beembedded in another device, e.g., a phone, an electronic appliance, amobile audio or video player, a game console, a Global PositioningSystem (GPS) receiver, or a portable storage device (e.g., a universalserial bus (USB) flash drive). Devices suitable for storing computerprogram instructions and data include all forms of non-volatile memory,media and memory devices, including by way of example semiconductormemory devices (e.g., EPROM, EEPROM, flash memory devices, and others),magnetic disks (e.g., internal hard disks, removable disks, and others),magneto optical disks, and CD ROM and DVD-ROM disks. In some cases, theprocessor and the memory can be supplemented by, or incorporated in,special purpose logic circuitry.

To provide for interaction with a user, operations can be implemented ona computer having a display device (e.g., a monitor, or another type ofdisplay device) for displaying information to the user and a keyboardand a pointing device (e.g., a mouse, a trackball, a tablet, a touchsensitive screen, or another type of pointing device) by which the usercan provide input to the computer. Other kinds of devices can be used toprovide for interaction with a user as well; for example, feedbackprovided to the user can be any form of sensory feedback, e.g., visualfeedback, auditory feedback, or tactile feedback; and input from theuser can be received in any form, including acoustic, speech, or tactileinput. In addition, a computer can interact with a user by sendingdocuments to and receiving documents from a device that is used by theuser; for example, by sending web pages to a web browser on a user'sclient device in response to requests received from the web browser.

A computer system may include a single computing device, or multiplecomputers that operate in proximity or generally remote from each otherand typically interact through a communication network. Examples ofcommunication networks include a local area network (“LAN”) and a widearea network (“WAN”), an inter-network (e.g., the Internet) andpeer-to-peer networks (e.g., ad hoc peer-to-peer networks). Arelationship of client and server may arise by virtue of computerprograms running on the respective computers and having a client-serverrelationship to each other.

In a general aspect, unique unclonable physical identifiers are appliedand used. In some implementations, a unique marker is shaped to amorphology of an object's surface feature. The surface feature can befacets, surface patterns, textures, or other indentations of the object.The unique marker can include a distribution of elements, and elementinformation is used to generate a code. In some examples, the elementinformation can include orientation information and possibly otherinformation describing diamond particles or other types of elements. Insome instances, the unique marker is a sticker including a distributionof elements on a substrate having an adhesive backing, and at least aportion of the sticker is applied to an object.

In a first example, an object that includes multiple elements isreceived. Orientation information is extracted from the object by ascanner system detecting the elements. The orientation informationindicates relative spatial orientations of the respective elements. Aunique code is generated for the object based on the orientationinformation.

Implementations of the first example may include one or more of thefollowing features. Extracting the orientation information can includeobtaining an optical response to illumination applied to the object.Extracting the orientation information can include obtainingfluorescence images of the object, determining the relative spatialorientations of the respective elements from the fluorescence images.Obtaining an optical response to illumination can include detectingfluorescence changes of the elements in response to changes in theillumination, and the relative spatial orientations can be determinedbased on detected fluorescence changes. The unique code generated fromthe orientation information can be independent of (e.g., invariant underchanges in) the angle or angles at which the illumination is applied tothe object.

Implementations of the first example may include one or more of thefollowing features. Extracting the orientation information can includeobtaining a magnetic resonance response to an oscillatory (e.g., radiofrequency, microwave, etc.) electromagnetic field applied to the object,and determining the relative spatial orientations based on the magneticresonance response. Obtaining the magnetic resonance response caninclude positioning the object in an external magnetic field, applyingthe oscillatory electromagnetic field to the object in the externalmagnetic field, and optically detecting magnetic resonance changes ofthe elements in response to relative changes (e.g., changes in fieldstrength or orientation) in the external magnetic field, relativechanges (e.g., relative changes in signal amplitude, frequency or phase)in the oscillatory electromagnetic field, or relative changes in both.The unique code generated from the orientation information can beindependent of (e.g., invariant under changes in) the angle or angles atwhich the oscillatory electromagnetic field and external magnetic fieldare applied to the object.

Implementations of the first example may include one or more of thefollowing features. The object can include a superset of elements, andthe unique code can be generated based on the relative spatialorientations of only a subset of elements, which includes less than allof the elements in the superset. The orientation information extractedfrom the object can indicate the relative spatial orientations of onlythe subset of elements. The orientation information extracted from theobject can indicate the relative spatial orientations of all theelements in the superset, and a subset of the orientation informationindicating relative spatial orientations of the subset can beidentified.

Implementations of the first example may include one or more of thefollowing features. The orientation information can be extractedindependent of registering the object relative to the scanner system.The orientation information can indicate the relative spatialorientations of the elements in a two-dimensional coordinate space or ina three-dimensional coordinate space. The orientation information canindicate the relative spatial orientations in a format that is invariantto global rotations of a coordinate system of the object.

Implementations of the first example may include one or more of thefollowing features. The orientation information can include a list ofcoordinate transformations (e.g., transformation matrices) describingthe relative spatial orientations of the respective elements. The listcan include a composite transformation matrix for each element. The listof composite transformation matrices can be invariant to globalrotations of the coordinate system of the object. In cases where theelements are diamond particles, the composite transformation matrix foreach element can represents a first transformation between a coordinatesystem of the object and a coordinate system of the diamond particle;and a second transformation between the coordinate system of the diamondparticle and a coordinate system of a color center in the diamondparticle.

Implementations of the first example may include one or more of thefollowing features. The elements can be crystalline particles, and theobject can include the crystalline particles fixed in a medium. Thecrystalline particles can be diamond particles that have respectivecolor centers, and extracting the orientation information can includedetecting the relative orientations of the color centers.

Implementations of the first example may include one or more of thefollowing features. Location information, indicating relative spatialpositions of the respective elements, can be extracted from the object.Topographical information, indicating relative spatial topographies ofthe respective elements, can be extracted from the object. Magneticenvironment information, indicating magnetic environments of therespective elements, can be extracted from the object. The unique codecan be generated from any combination of location information,topographical information, magnetic environment information andorientation information.

Implementations of the first example may include one or more of thefollowing features. The unique code can be a first unique code, and therelative spatial orientations of at least some of the elements can bechanged by modifying the object. A second, different unique code for theobject can be generated based on orientation information extracted fromthe object after changing the relative spatial orientations. Therelative spatial orientations can be used, for example, as a ledger forinformation related to the object.

Implementations of the first example may include one or more of thefollowing features. The scanner system can include a sample region, aprobe and a processor. The sample region can be configured to receivethe object. The probe can be configured to extract orientationinformation from the object by detecting the elements. The processor canbe configured to generate the unique code for the object based on theorientation information. The probe can include an optical imaging system(e.g., a fluorescence imaging system) configured to extract theorientation information by applying illumination to the object andobtaining optical responses (e.g., fluorescence responses) to theillumination. In some cases, optical imaging systems can be configuredto obtain an optical response based on Raman scattering or anothernonlinear effect (e.g., second harmonic generation, spontaneousparametric down conversion, etc.). The probe can include a magneticresonance system configured to extract the orientation information byapplying fields (e.g., an oscillatory electromagnetic field and anexternal magnetic field) to the object and obtaining magnetic resonanceresponses to the fields.

In a second example, orientation information indicating relative spatialorientations of respective elements of an object is obtained. A uniquecode for the object from the orientation information.

Implementations of the second example may include one or more of thefollowing features. The unique code can be used in a challenge-responseprotocol. The orientation information can be extracted based onchallenge data for the challenge-response protocol, the unique code canbe used to generate response data for the challenge-response protocol,and the response data can be sent to an authenticator.

Implementations of the second example may include one or more of thefollowing features. The unique code can be used in an authenticationprocess. The authentication process can be executed to authenticate asource of the object. The authentication process can be executed toverify integrity of the object. The authentication process can beexecuted to verify a chain of custody of the object.

Implementations of the second example may include one or more of thefollowing features. The unique code can be used in a cryptographicprocess. The unique code can be used to obtain a secret key for anencryption protocol, a digital signature protocol or another type ofcryptographic process.

Implementations of the second example may include one or more of thefollowing features. The object can include a superset of elements, andthe unique code can be generated based on the relative spatialorientations of only a subset of elements, which includes less than allof the elements in the superset. The orientation information canindicate the relative spatial orientations of the elements in atwo-dimensional coordinate space or in a three-dimensional coordinatespace. The orientation information can indicate the relative spatialorientations in a format that is invariant to global rotations of acoordinate system of the object.

Implementations of the second example may include one or more of thefollowing features. The orientation information can include a list ofcoordinate transformations (e.g., transformation matrices) describingthe relative spatial orientations of the respective elements. The listcan include a composite transformation matrix for each element. The listof composite transformation matrices can be invariant to globalrotations of the coordinate system of the object. In cases where theelements are diamond particles, the composite transformation matrix foreach element can represents a first transformation between a coordinatesystem of the object and a coordinate system of the diamond particle;and a second transformation between the coordinate system of the diamondparticle and a coordinate system of a color center in the diamondparticle.

In a third example, a suspension of elements is formed in an object, andthe suspension of elements is used to generate a unique code for theobject. The suspension of elements can be, for example, a suspension ofdiamond particles.

Implementations of the third example may include one or more of thefollowing features. The suspension can be formed by distributing diamondparticles on a surface of the object. Distributing the diamond particleson a surface of the object can include applying, to the surface of theobject, paint that contains the diamond particles. Distributing thediamond particles on a surface of the object can include applying, tothe surface of the object, conformal coating material that contains thediamond particles.

Implementations of the third example may include one or more of thefollowing features. The suspension can be formed by distributing thediamond particles in a material and forming the object from the materialcontaining the diamond particles. Forming the object from the materialcan include forming the object by an injection molding process. Formingthe object from the material can include forming the object by anadditive manufacturing process. Forming the object from the material caninclude forming the object by a printing process. Forming the objectfrom the material can include forming a workpiece from the material andremoving material from the workpiece.

Implementations of the third example may include one or more of thefollowing features. The object is sent from a sending entity to areceiving entity, and the unique code is used in an analysis processexecuted between the sending entity and the receiving entity. Thesuspension of diamond particles is used as a physically unclonablefunction (PUF), a ledger for information related to the object orotherwise.

Implementations of the third example may include one or more of thefollowing features. A manufacturing system is configured to form thesuspension of diamond particles in the object. A scanner system isconfigured to extract particle information from the object, and theparticle information indicates properties of the respective diamondparticles in the suspension. A computer system is configured to generatethe unique code for the object based on the particle information.

In a fourth example, orientation information indicating relative spatialorientations of respective elements of an object is received. A uniquecode is generated from the orientation information. The unique code isassociated with an object identifier of the object.

Implementations of the fourth example may include one or more of thefollowing features. The object can include a unique marker applied to anarticle, and the object identifier can be a serial number of thearticle. The article can be distributed, and the unique code and theserial number can be stored in a secure database. The orientationinformation can be extracted from the unique marker by operation of ascanner system, and the scanner settings used by the scanner system toextract the orientation information can be stored in the securedatabase. The unique marker can enable a recipient of the article toanalyze the article.

In a fifth example, an analysis process is performed. The analysisprocess includes receiving an object identifier for an object; receivinga unique code for the object, the unique code being based on detectedrelative orientations of respective elements of the object; andanalyzing the object based on the unique code and the object identifier.

Implementations of the fifth example may include one or more of thefollowing features. The object can include a unique marker applied to anarticle, and the object identifier can include a serial number of thearticle. Analyzing the object can include communicating the unique codeand the object identifier to an authenticator. Analyzing the object caninclude evaluating the unique code based on information in a securedatabase. Analyzing the object can include executing an authenticationprocess to authenticate a source of the object, to authenticateintegrity of the object, or to authenticate a chain of custody of theobject.

In a sixth example, a challenge-response protocol is performed.Challenge data for the challenge-response protocol is obtained. Based onthe challenge data, orientation information is extracted from an objectby operation of a scanner system detecting the relative spatialorientations of respective elements of the object. The challenge datainclude a parameter used by the scanner system to detect the relativespatial orientations. Based on the orientation information, responsedata are generated for the challenge-response protocol.

Implementations of the sixth example may include one or more of thefollowing features. The response data can be sent to a validator toverify the response data for the challenge-response protocol. An outcomeof the challenge-response protocol, based on the challenge data and theresponse data, can be received from the validator. Obtaining thechallenge data can include receiving the challenge data from thevalidator. Obtaining the challenge data can include generating thechallenge data at the scanner system.

In a seventh example, a challenge-response protocol is performed.Challenge data and response data for the challenge-response protocol areobtained. The challenge data include a parameter for extractingorientation information from an object, and the response data are basedon orientation information extracted from the object (e.g., by a scannersystem) using the parameter. The orientation information indicaterelative spatial orientations of respective elements of the object. Thechallenge data and response data are used to determine whether theresponse data represent a valid response to the challenge data.

Implementations of the seventh example may include one or more of thefollowing features. Determining whether the response data represent avalid response to the challenge data can include evaluating theorientation information based on valid information in a secure database.The valid information can be obtained from the secure database based onthe challenge data and an object identifier of the object. A validatorcan receive the challenge data and the response data from a remotescanner system, and the validator can send the remote scanner system anindication of whether the response data represent a valid response.

Implementations of the fourth, fifth, sixth and seventh examples mayinclude one or more of the following features. The elements can bediamond particles that have respective color centers, and theorientation information can be extracted by detecting relativeorientations of the color centers. Extracting the orientationinformation can include obtaining an optical response (e.g., afluorescence response) to illumination applied to the diamond particles.The orientation information may be extracted by optically detectedmagnetic resonance of the diamond particles. The unique code and theobject identifier can be used in an analysis process to analyze theobject.

In an eighth example, a method includes receiving an object having asurface feature and forming a unique marker on the surface feature ofthe object. The unique marker includes a distribution of elements andconforms with a morphology of the surface feature. The method furtherincludes extracting orientation information from the unique marker. Theorientation information indicates relative spatial orientations of therespective elements. The method additionally includes generating aunique code for the object based on the orientation information.

Implementations of the eighth example may include one or more of thefollowing features. The elements can be crystalline particles, and theunique marker includes the crystalline particles fixed in a medium. Thecrystalline particles can be diamond particles including respectivecolor centers, and extracting the orientation information can includedetecting relative orientations of the color centers. The surfacefeature can include an indentation, and forming the unique marker on thesurface feature includes forming a fluid containing the distribution ofelements in the indentation, and exposing the fluid in the indentationto a hardening process that causes the fluid to harden and form theunique marker. The hardening process includes at least one of a dryingprocess (e.g., exposure to the atmosphere at room temperature), a curingprocess (e.g., a process that uses a curing agent, such as a catalyst ora hardener, examples being tertiary amines, Lewis acids, aliphatic andaromatic amines, or carboxylic anhydrides), or exposure to an energysource (e.g., lamps, examples being mercury-vapor lamps orlight-emitting diode (LED) lamps). The energy source (e.g.,mercury-vapor lamps or LED lamps) may be configured to emit ultravioletradiation. The fluid includes at least one of a resin material, an epoxymaterial, an acrylic material, a urethane material, a silicone material,a xylene material, a toluene material, an ethyl acetate material, or anink. Forming the fluid containing the distribution of elements in theindentation includes applying the fluid to the object to fill theindentation, and removing excess material of the fluid from a surface ofthe object. Removing the excess material of the fluid from the surfaceof the object includes using a removal instrument to remove the excessmaterial of the fluid from the surface of the object. The removalinstrument includes at least one of a doctor blade, a spatula, or asqueegee. Forming the fluid containing the distribution of elements inthe indentation includes using a flexography printing system to form thefluid containing the distribution of elements in the indentation of theobject, or using a rotogravure system to form the fluid containing thedistribution of elements in the indentation of the object, or acombination of these.

Implementations of the eighth example may include one or more of thefollowing features. Forming the fluid containing the distribution ofelements in the indentation includes using the flexography printingsystem, and multiple cells are present on a surface of an anilox rollerof the flexography printing system. A width of each cell at its widestdimension can be in a range from about 20 microns to about 300 microns.Forming the fluid containing the distribution of elements in theindentation includes using the flexography printing system, and multiplecells are present on a surface of an anilox roller of the flexographyprinting system, where the multiple cells include a first group of cellsand a second group of cells. A volume of each cell in the first group ofcells can be greater than a volume of each cell in the second group ofcells, and the volume of each cell in the first group of cells can be atleast an order of magnitude larger than an average width of theelements. The surface feature includes a facet of the object, andforming the unique marker on the surface feature includes forming theunique marker as a conformal layer on the facet of the object. Thesurface feature includes a surface of one or more components of theobject, and forming the unique marker on the surface feature includesforming the unique marker as a conformal layer on the one or morecomponents of the object. The surface feature includes a region of theobject susceptible to tampering, and forming the unique marker on thesurface feature includes forming the unique marker on the region of theobject susceptible to tampering. In some instances, the region of theobject susceptible to tampering can be any area of the object (e.g.,product or the product's packaging) that can be opened or breached, thusallowing a third party to alter a shape of the object or to access thecontents of the object.

In a ninth example, a method includes providing a sticker including adistribution of elements on a substrate having an adhesive backing, andapplying at least a portion of the sticker on an object. The methodfurther includes extracting orientation information from the portion ofthe sticker on the object. The orientation information can indicaterelative spatial orientations of the respective elements of the portionof the sticker on the object. The method additionally includesgenerating a unique code for the object based on the orientationinformation.

Implementations of the ninth example may include one or more of thefollowing features. The portion of the sticker may be applied to aregion of the object susceptible to tampering. The sticker includes afirst portion and a second portion, and applying at least a portion ofthe sticker on the object may include: separating the first portion ofthe sticker from the second portion of the sticker; and applying thefirst portion of the sticker on the object. Before applying the firstportion of the sticker on the object, initial orientation informationmay be extracted from the sticker. The initial orientation informationmay indicate relative spatial orientations of the respective elements ofthe first and second portions of the sticker. An initial unique code maybe generated based on the initial orientation information, and theinitial unique code may be associated with the sticker. After applyingthe first portion of the sticker on the object, second orientationinformation may be extracted from the second portion of the sticker. Thesecond orientation information can be indicative of relative spatialorientations of the respective elements of the second portion of thesticker. A second unique code is generated based on the secondorientation information. The second unique code is associated with thesecond portion of the sticker and to application of the first portion ofthe sticker on the object.

In some implementations, a system includes a manufacturing apparatusconfigured to receive an object having a surface feature and to form aunique marker on the surface feature of the object, the unique markerincluding a distribution of elements and conforming with a morphology ofthe surface feature. The system further includes a scanner systemconfigured to extract orientation information from the unique marker,the orientation information indicating relative spatial orientations ofthe respective elements. The system additionally includes a computersystem configured to generate a unique code for the object based on theorientation information.

While this specification contains many details, these should not beunderstood as limitations on the scope of what may be claimed, butrather as descriptions of features specific to particular examples.Certain features that are described in this specification or shown inthe drawings in the context of separate implementations can also becombined. Conversely, various features that are described or shown inthe context of a single implementation can also be implemented inmultiple embodiments separately or in any suitable sub combination.

Similarly, while operations are depicted in the drawings in a particularorder, this should not be understood as requiring that such operationsbe performed in the particular order shown or in sequential order, orthat all illustrated operations be performed, to achieve desirableresults. In certain circumstances, multitasking and parallel processingmay be advantageous. Moreover, the separation of various systemcomponents in the implementations described above should not beunderstood as requiring such separation in all implementations, and itshould be understood that the described program components and systemscan generally be integrated together in a single product or packagedinto multiple products.

A number of embodiments have been described. Nevertheless, it will beunderstood that various modifications can be made. Accordingly, otherembodiments are within the scope of the following claims.

1. A method, comprising: receiving an object having a surface feature;forming a unique marker on the surface feature of the object, the uniquemarker comprising a distribution of elements and conforming with amorphology of the surface feature; extracting orientation informationfrom the unique marker, the orientation information indicating relativespatial orientations of the respective elements; and generating a uniquecode for the object based on the orientation information.
 2. The methodof claim 1, wherein the elements are crystalline particles, and theunique marker comprises the crystalline particles fixed in a medium. 3.The method of claim 2, wherein the crystalline particles are diamondparticles comprising respective color centers, and extracting theorientation information comprises detecting relative orientations of thecolor centers.
 4. The method of claim 1, wherein the surface featurecomprises an indentation, and forming the unique marker on the surfacefeature comprises: forming a fluid containing the distribution ofelements in the indentation; and exposing the fluid in the indentationto a hardening process that causes the fluid to harden and form theunique marker.
 5. The method of claim 4, wherein the hardening processcomprises at least one of a drying process, a curing process, orexposure to an energy source.
 6. The method of claim 5, wherein thehardening process comprises exposure to an energy source configured toemit ultraviolet radiation.
 7. The method of claim 4, wherein the fluidcomprises at least one of a resin material, an epoxy material, anacrylic material, a urethane material, a silicone material, a xylenematerial, a toluene material, an ethyl acetate material, or an ink. 8.The method of claim 4, wherein forming the fluid containing thedistribution of elements in the indentation comprises: applying thefluid to the object to fill the indentation; and removing excessmaterial of the fluid from a surface of the object.
 9. The method ofclaim 8, wherein removing the excess material of the fluid from thesurface of the object comprises using a removal instrument to remove theexcess material of the fluid from the surface of the object.
 10. Themethod of claim 9, wherein the removal instrument comprises at least oneof a doctor blade, a spatula, or a squeegee.
 11. The method of claim 4,wherein forming the fluid containing the distribution of elements in theindentation comprises at least one of: using a flexography printingsystem to form the fluid containing the distribution of elements in theindentation of the object; or using a rotogravure system to form thefluid containing the distribution of elements in the indentation of theobject.
 12. The method of claim 11, wherein forming the fluid containingthe distribution of elements in the indentation comprises using theflexography printing system, and wherein: a surface of an anilox rollerof the flexography printing system includes multiple cells, and a widthof each cell at its widest dimension is in a range from about 20 micronsto about 300 microns.
 13. The method of claim 11, wherein forming thefluid containing the distribution of elements in the indentationcomprises using the flexography printing system, and wherein: a surfaceof an anilox roller of the flexography printing system includes multiplecells, the multiple cells comprising a first group of cells and a secondgroup of cells, a volume of each cell in the first group of cells isgreater than a volume of each cell in the second group of cells, and thevolume of each cell in the first group of cells is at least an order ofmagnitude larger than an average width of the elements.
 14. The methodof claim 1, wherein the surface feature comprises a facet of the object,and forming the unique marker on the surface feature comprises formingthe unique marker as a conformal layer on the facet of the object. 15.The method of claim 1, wherein the surface feature comprises a surfaceof one or more components of the object, and forming the unique markeron the surface feature comprises forming the unique marker as aconformal layer on the one or more components of the object.
 16. Themethod of claim 1, wherein the surface feature comprises a region of theobject susceptible to tampering, and forming the unique marker on thesurface feature comprises forming the unique marker on the region of theobject susceptible to tampering.
 17. A system, comprising: amanufacturing apparatus configured to receive an object having a surfacefeature and to form a unique marker on the surface feature of theobject, the unique marker comprising a distribution of elements andconforming with a morphology of the surface feature; a scanner systemconfigured to extract orientation information from the unique marker,the orientation information indicating relative spatial orientations ofthe respective elements; and a computer system configured to generate aunique code for the object based on the orientation information.
 18. Thesystem of claim 17, wherein the elements are crystalline particles, andthe unique marker comprises the crystalline particles fixed in a medium.19. The system of claim 18, wherein the crystalline particles arediamond particles comprising respective color centers, and extractingthe orientation information comprises detecting relative orientations ofthe color centers.
 20. The system of claim 17, wherein the surfacefeature comprises an indentation, and forming the unique marker on thesurface feature comprises: forming a fluid containing the distributionof elements in the indentation; and exposing the fluid in theindentation to a hardening process that causes the fluid to harden andform the unique marker.
 21. The system of claim 20, wherein thehardening process comprises at least one of a drying process, a curingprocess, or exposure to an energy source.
 22. The system of claim 21,wherein the hardening process comprises exposure to an energy sourceconfigured to emit ultraviolet radiation.
 23. The system of claim 20,wherein the fluid comprises at least one of a resin material, an epoxymaterial, an acrylic material, a urethane material, a silicone material,a xylene material, a toluene material, an ethyl acetate material, or anink.
 24. The system of claim 20, wherein forming the fluid containingthe distribution of elements in the indentation comprises: applying thefluid to the object to fill the indentation; and removing excessmaterial of the fluid from a surface of the object.
 25. The system ofclaim 24, wherein the manufacturing apparatus comprises a removalinstrument, and removing the excess material of the fluid from thesurface of the object comprises using the removal instrument to removethe excess material of the fluid from the surface of the object.
 26. Thesystem of claim 25, wherein the removal instrument comprises at leastone of a doctor blade, a spatula, or a squeegee.
 27. The system of claim20, wherein the manufacturing apparatus comprises at least one of: aflexography printing system configured to receive the object and formthe fluid containing the distribution of elements in the indentation ofthe object; or a rotogravure system configured to receive the object andform the fluid containing the distribution of elements in theindentation of the object.
 28. The system of claim 27, wherein themanufacturing apparatus comprises the flexography printing system, andwherein: a surface of an anilox roller of the flexography printingsystem includes multiple cells, and a width of each cell at its widestdimension is in a range from about 20 microns to about 300 microns. 29.The system of claim 27, wherein the manufacturing apparatus comprisesthe flexography printing system, and wherein: a surface of an aniloxroller of the flexography printing system includes multiple cells, themultiple cells comprising a first group of cells and a second group ofcells, a volume of each cell in the first group of cells is greater thana volume of each cell in the second group of cells, and the volume ofeach cell in the first group of cells is at least an order of magnitudelarger than an average width of the elements.
 30. The system of claim17, wherein the surface feature comprises a facet of the object, andforming the unique marker on the surface feature comprises forming theunique marker as a conformal layer on the facet of the object.
 31. Thesystem of claim 17, wherein the surface feature comprises a surface ofone or more components of the object, and forming the unique marker onthe surface feature comprises forming the unique marker as a conformallayer on the one or more components of the object.
 32. The system ofclaim 17, wherein the surface feature comprises a region of the objectsusceptible to tampering, and forming the unique marker on the surfacefeature comprises forming the unique marker on the region of the objectsusceptible to tampering. 33-37. (canceled)